Một vật nhỏ dao động có đồ thị giữa li độ và thời gian như hình . Nhận định nào đúng, nhận định nào sai?

Nội dung	Đúng	Sai
a. Tần số dao động của vật là 1,5 Hz
b. Chiều dài quỹ đạo dao động của vật là 4 cm.
c. Ở thời điểm  vật chuyển động qua vị trí x = -2 theo chiều âm.
d. Tốc độ trung bình khi vật đi được quãng đường 13 cm là 19,5 s.

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 from 13 to 17.

a. Tom: Why a cooking class?

b. Sarah: I'm planning to take a cooking class.

c. Tom: How are you going to learn to cook?

d. Tom: I think classes can be quite pricey. I might just watch videos instead.

e. Sarah: They teach hands-on skills, and it’s fun to cook with others.

Khi nuôi tôm, cá với mật độ cao người ta thường dùng máy sục khí vào nước nuôi nhằm

Đâu là biện pháp giúp bảo vệ đất trồng?

Cho đoạn tư liệu sau đây:

“Việt Nam luôn ủng hộ các mục tiêu hàng đầu của Liên hợp quốc, như duy trì hòa bình và an ninh, chống chạy đua vũ trang, giải trừ quân bị, ngăn ngừa và giải quyết các tranh chấp, xung đột bằng biện pháp hòa bình, tăng cường quan hệ hữu nghị giữa các dân tộc. Việt Nam cũng là nước tham gia ký kết nhiều điều ước quốc tế do Liên hợp quốc tổ chức”.

(https://tapchicongsan.org.vn/quoc-phong-an-ninh-oi-ngoai1/-/2018/47741/lien-hop-quoc-va-nhung-dong-gop-cua-viet-nam.aspx)

Một chủng vi khuẩn Escherichia coli mang đột biến làm thay đổi trình tự nucleotide ở vùng vận hành (operator) của operon lac làm giảm ái lực với protein ức chế. Nhận định nào sau đây về sự phiên mã của các gene cấu trúc trong operon lac ở chủng vi khuẩn này là đúng?

Complete the following sentences with the correct forms of the words in capitals

He made a major _______________________  to peace in the region. (CONTRIBUTE)

Xác định ý đúng: Nguyên liệu sản xuất phân bón hóa học là gì?

Read the following passage about food addiction 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.

Few people would disagree that one of the world's most popular dishes is pizza. Twenty-two-year-old Zack certainly wouldn't. He would eat a variety of pizza-based items, including homemade pizza, precooked microwave pizza, and even pizza leftovers from the night before. He was consuming 800kg of pizza a year. As a child, Zack had eaten a wide variety of food. But he became addicted to pizza when he started secondary school. American school meals have often been criticised for the large amount of fast food present on the menu, and pizza is the star dish. Zack even spent all his pocket money on slices of pizza.

Naturally, Zack's family worried about his high-calorie, low-vitamin diet. So did Zack. In an attempt to break his addiction, Zack agreed to appear on a TV programme called Freaky Eaters. Its aim was to encourage food addicts to beat their addictions with the help of a psychologist and nutritionist. It wasn't easy. He had to eat a fish dish, while his brother sat in front of him enjoying... a pizza! However, Zack met the challenge and has never eaten pizza again.

Seventeen-year-old Stacy Irvine's friends visit her and discover that she has been rewarded thousands of free toys from fast food restaurants as a regular customer. Stacy's mother often gave her two-year-old girl a portion of fried chicken in a McDonald's restaurant. [I] Since then, Stacy has refused to eat anything else except for pieces of fried chicken, and as a result, her diet has created serious health. She has been warned that if she doesn't change her diet, she will die. [II] Stacy once collapsed due to lack of vitamins and nutrients and needed to be hospitalised. [III] She insisted that Stacy adopt a healthier lifestyle. However, worryingly, Stacy's mother said that while Stacy was beginning to understand the seriousness of her situation, she couldn't eat anything else but chicken nuggets. [IV]

Twenty-year-old Hanna Little was keen on chips. The only thing that Hanna consumed for fifteen years was one plate of chips after another. Not surprisingly, a diet that contained few nutrients and an excess of fat and carbohydrates could only have negative consequences. And it did because not only did Hanna develop health problems, but she also had to leave her job after collapsing at work. At five, Hanna became addicted to chips and refused to eat fruits and vegetables despite her mother's efforts. Hanna says that she was terrified of tasting the flavour of different types of food and she would feel anxious just at the idea of doing it. Parties, picnics and barbecues with friends and family used to be a nightmare. Furthermore, Hanna was soon seen as 'odd' by her friends' parents.

It wasn't until the age of sixteen that Hanna realised she had Selective Eating Disorder (SED). Despite this new knowledge, no solution was found. It wasn't until she lost her job before she started eating normally. Hanna sought therapy from psychologist Felix Economakis, who used hypnosis, a treatment that none of the doctors that she had seen before had mentioned, to get her to eat fruit after one one-hour session, and since then she has been willing to eat anything.... including chips!

(Adapted from Friends Global)

Which of the following best paraphrases the underlined sentence in paragraph 4?

Quy trình số hóa âm thanh được hiểu là

Một bệnh viện thống kê chiều cao của 50 trẻ sơ sinh 12 ngày tuổi một cách ngẫu nhiên. Kết quả thu được như sau:

Bộ giá trị nào sau đây là tứ phân vị của mẫu số liệu ghép nhóm trên?

Mệnh đề nào sau đây đúng?

Read the passage carefully. Choose an option (A, B, C, or D) that best answers each question from to 646 to 650:

1. Millions of people are using cellphones today. In many places, it is actually considered unusual not to use one. In many countries, cellphones are very popular with young people. They find that the phones are more than a means of communication - having a mobile phone shows that they are cool and connected.

2. The explosion in mobile phone use around the world has made some health professionals worried. Some doctors are concerned that in the future many people may suffer health problems from the use of mobile phones. In England, there has been a serious debate about this issue. Mobile phone companies are worried about the negative publicity of such ideas. They say that there is no proof that mobile phones are bad for your health.

3. On the other hand, medical studies have shown changes in the brain cells of some people who use mobile phones. Signs of change in the tissues of the brain and head can be detected with modern scanning equipment. In one case, a traveling salesman had to retire at young age because of serious memory loss. He couldn't remember even simple tasks. He would often forget the name of his own son. This man used to talk on his mobile phone for about six hours a day, every day of his working week, for a couple of years. His family doctor blamed his mobile phone use, but his employer's doctor didn't  agree.

4. What is it that makes mobile phones potentially harmful? The answer is radiation. High-tech machines can detect very small amounts of radiation from mobile phones. Mobile phone companies agree that there is some radiation, but they say the amount is too small to worry about.

5. As the discussion about their safety continues, it appears that it's best to use mobile phones less often. Use your regular phone if you want to talk for a long time. Use your mobile phone only when you really need it. Mobile phones can be very useful and convenient, especially in emergencies. In the future, mobile phones may have a warning label that says they are bad for your health. So for now, it's wise not to use your mobile phone too often.

What could be the most suitable title for the passage?

Nội dung nào sau đây phản ánh đúng đặc trưng của chủ nghĩa đế quốc?