Glycerol có công thức là \({{\text{C}}_{3}}{{\text{H}}_{5}}{{(\text{OH})}_{3}}\), được sử dụng để kiểm soát độ ẩm và giúp tăng cường độ kết dính trong kem dưỡng da. Nhận định đúng về glycerol là:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 18 to 22.

     Technology can exert its power on almost every aspect of our lives, and personal relationships are no exception. We are now becoming more attached to technological devices and less connected to the people around us or even our loved ones (18)_________.

     We work longer hours on computers, meet fewer friends, text more often, and watch more videos than have a true conversation with friends or family members. Relationships at home and at work (19)_______. Social media links us all together, but we mistake them for a perfect replacement for relationships. It is time we realised that the power of connections is built from our own efforts. Choosing to stay technologically connected, (20_________, listening, understanding, and sharing feelings. (21)_________.

     It is not difficult to balance between connections through technology and those through real interactions. (22)_________. We should spend more time visiting our parents and siblings, besides keeping in touch with them on social media. We should learn to cherish the moments we spend with them. It is never too late to strengthen the bonds with school friends and teachers.      

Việc phe Hiệp ước không hưởng ứng lời kêu gọi hòa bình của Chính phủ Xô viết đã dẫn đến hệ quả gì:

Từ khi lập nước đến nay, nước ta có bao nhiêu bản Hiến pháp?

Cho bất phương trình \(\log _{2}\left(5^{x}-1\right) \leq m\).

Gọi \(S\) là tập tất cả các giá trị nguyên của \(m\) sao cho bất phương trình có đúng 3 nghiệm nguyên. Số phần tử của \(S\) là

Nhận định nào không đúng khi nói về sự khác nhau giữa sinh trưởng sơ cấp và sinh trưởng thứ cấp?

Các lĩnh vực trao đổi và mua bán mà ở đó các chủ thể kinh tế có thể tác động qua lại lẫn nhau để xác định giá cả và số lượng hàng hoá, dịch vụ được gọi là gì?

Sử dụng các kí hiệu đoạn, khoảng, nửa khoảng để viết tập hợp $A = \{ x \in \mathbb{R} \big| x < 2\}$.

Xã hội Việt Nam đầu thời Nguyễn phân chia thành những giai cấp nào?

Các phản ứng trong quá trình hô hấp nội bào được nhận xét thực hiện nhờ sự có mặt của?

Bộ máy nhà nước Việt Nam được tổ chức và hoạt động theo nguyên tắc nào?

1. Do you find yourself yawning all day at school? You probably need more sleep. However, it is not just how much sleep you get that is important. What you do before bedtime also has a huge effect on how you feel the next day. If you spend time chatting to someone on social media, or reading a book on your e- reader, you are not alone.

2. All devices' screens give out a large amount of blue light, which affects the body's production of the sleep hormone, melatonin, which can change your sleep patterns. So it is not just getting to sleep that becomes hard, but the quality of your sleep also suffers. The result is that you can wake up several times during the night, and have difficulty getting up in the morning.

3. Sleep is food for the brain, so not sleeping well can be a severe problem for anyone, especially for teenagers, because their brains are still developing. When you do not sleep well, it can be difficult to concentrate at school, which makes it harder to learn and get good grades. It can also affect your mood, making you feel sad or anxious.   

4. So, it is clear you should not use your phone before you go to sleep. Why not leave it in another room? Nothing on social media is so important that it cannot wait a few hours! You should rediscover paper books and enjoy feeling tired and sleepy before bedtime rather than wondering why your best friend has not liked your photo! How will you wake up? You do not have to use the alarm on your phone. Go and buy yourself an old-fashioned alarm clock! The negative effects that screen time is having on sleep have been in the news a lot recently, so manufacturers of smartphones and tablets have added a feature to the mobile devices that can help reduce these. Most new phones have a night-time setting that changes the colour of the screen so that it gives out less blue light. If you really cannot avoid going onto social media at bedtime, think about turning on this setting on your phone.

Which of the following can be inferred from the reading passage?  

Sản phẩm chăn nuôi nào dưới đây không được dùng làm thực phẩm?

Đâu là thành phần chủ yếu của dầu thực vật?

Hai con lắc lò xo giống hệt nhau đặt trên cùng mặt phẳng nằm ngang. Con lắc thứ nhất và con lắc thứ hai dao động điều hòa cùng pha với biên độ lần lượt là 3A và A. Chọn mốc thế năng của mỗi con lắc tại vị trí cân bằng của nó. Khi động năng của con lắc thứ nhất là 0,72 J thì thế năng của con lắc thứ hai là 0,24 J. Khi thế năng của con lắc thứ nhất là 0,09 J thì động năng của con lắc thứ hai là

Tổ chức Du lịch Thế giới viết tắt là gì?

Read the following passage about education in Nepal and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions from 31 to 40. 

Fashion in the 1960s reflected the cultural and political upheaval of the time. The hippie and counterculture movement gave rise to accessories like Pocahontas-style headbands and medallions worn around the neck. Hippies wore long, loosely fitting clothing, often in natural fabrics. Hemlines rose as Mary Quant popularized the miniskirt and hot pants in her lines for JC Penney. And mod fashion, with brightly colored space-age geometric patterns, shift dresses and colored tights became the mainstream. Both miniskirts and mod-shift dresses were worn with knee-high go-go boots.

[A] During the 1970s, the loose-fitting hippie clothes of the prior decade gave way to exotic fabrics and bell-bottom jeans for men and women. Hemlines continued to rise and hot pants continued their popularity, reflecting the flashy style of the decade. However, the 1970s also saw the popularity of a longer hemline, from mid-calf to ankle-length. [B] Women wore peasant-style clothing, especially blouses with off-the-shoulder necklines and lace trim, with their jeans or skirts. [C] Disco fashion emerged, featuring bright patterns and tightly fitting clothing meant to show off the body. Platform shoes elevated their wearer, male or female, anywhere from two to four inches or more. [D]

The 1980s saw another fashion upheaval. Angst-ridden punks wore Dr. Marten and steel-toed army boots, chains, tartan patterns, and bondage pants. Punks focused more on their hair during this period, dying, teasing and chopping their hair into asymmetric styles that seemed to defy gravity. Women—and men—experimented with heavy eyeliner in a variety of colors. Women wore neon colors, jelly shoes, tight jeans, leggings, leg warmers and oversized sweatshirts. Menswear-inspired looks also became popular for both sexes. Men wore ‘power suits,’ named so for their price, which made these suits a reflection of the wealth of the wearer. Women’s jackets featured big shoulder pads that made the shoulders appear higher and larger, similar to the male silhouette.

1990’s fashion was far more subdued than the garish, wild styles of the 1980s. Bands like Nirvana influenced the grunge look, which featured rock-concert tee shirts under plaid flannel shirts, jeans and long, greasy hair. Overalls were worn by both sexes, either with one or both shoulder straps unhooked. The punk style of the 1870s and 1980s evolved into the goth fashion trend, which featured black clothing, black boots and studded bracelets in the style of bands like Nine Inch Nails and Marilyn Manson.

Where does the following sentence best fit?

Embroidered clothing became especially popular with this trend.

Mark the letter A, B, C, or D on your answer sheet to indicate the best arrangement of utterances or sentences to make a meaningful exchange or text in each of the following questions.

a. John: Hi, David. Have you seen the new movie that came out last week?

b. John: It’s a sci-fi thriller with a lot of action and a great storyline.

c. David: Hi, John. I haven’t seen it yet. What’s it about?

Đâu không phải là phương pháp thường được áp dụng trong nghiên cứu sinh học?