Trong không gian với hệ trục tọa độ , mặt phẳng có một vectơ pháp tuyến là:

Trên Trái Đất, giờ khu vực phía Tây đến muộn hơn giờ ở khu vực phía Đông là do

Đại biểu Hội đồng nhân dân có những trách nhiệm gì với cử tri?

Phương trình mặt cầu có tâm $A(-1;-1;3)$ và tiếp xúc với mặt phẳng $zOx$ là:

Read the passage below and choose A, B, C or D.

Although noise, commonly defined as unwanted sound, is a widely recognized form of pollution, it is very difficult to measure because the discomfort experienced by different individuals is highly subjective and, therefore, variable. Exposure to lower levels of noise may be slightly irritating, whereas exposure to higher levels may actually cause hearing loss. Particularly in congested urban areas, the noise produced as a by-product of our advancing technology causes physical and psychological harm, and detracts from the quality of life for those who are exposed to it.

Unlike the eyes, which can be covered by the eyelids against strong light, the ear has no lid, and is, therefore, always open and vulnerable; noise penetrates without protection. Noise causes effects that the hearer cannot control and to which the body never becomes  accustomed. Loud noises instinctively signal danger to any organism with a hearing mechanism, including human beings. In response, heartbeat and respiration accelerate, blood vessels constrict, the skin pales, and muscles tense. In fact, there is a general increase in functioning brought about by the flow of adrenaline released in response to fear, and some of these responses persist even longer than the noise, occasionally as long as thirty minutes after the sound has ceased.

Because noise is unavoidable in a complex, industrial society, we are constantly responding in the same way that we would respond to danger. Recently, researchers have concluded that noise and our response may be much more than an annoyance. It may be a serious threat to physical and psychological health and well-being, causing damage not only to the ear and brain but also to the heart and stomach. We have long known that hearing loss is America's number one nonfatal health problem, but now we are learning that some of us with heart disease and ulcers may be victims of noise as well. Fetuses exposed to noise tend to be overactive, they cry easily, and they are more sensitive to gastrointestinal problems after birth. In addition, the psychic effect of noise is very important. Nervousness, irritability, tension, and anxiety increase affecting the quality of rest during sleep, and the efficiency of activities during waking hours, as well as the way that we interact with each other.

Based on the passage, how does noise affect psychological and physical health in industrial societies?

Trong các hàm số sau, hàm số nào nghịch biến trên \(\mathbb{R}\)?

Chi tiết Diêm Vương xử kiện nói lên điều gì?

Trên mặt chất lỏng có hai nguồn dao động S₁ và S₂ cùng phương, cùng phương trình dao động $u=a\cos2\pi ft$. Bước sóng là $\lambda$. Khoảng cách giữa hai điểm liên tiếp trên đoạn S₁S₂ dao động với biên độ cực đại là

Read the following leaflet 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 35 to 40.

How to Live Your Life Actively?

If you are not naturally sporty, and finding ways to fit more activity into your daily life, here are several tips to help you make a routine (35) ____________ being active:

Select a realistic exercise plan.

Track your progress using a health app (36) ____________ a paper checklist.

Take every opportunity to do such strength-building activities as carrying (37) ____________ and climbing the stairs.

Invite friends and (38) ____________ family members to join in, and try (39) ____________ everyone's competitive side with challenges like seeing who can do the most steps or cover the most distance in a day.

Reward yourself with a treat like a favourite TV show if your plan works (40) ____________ to maintain your motivation.

(Adapted from https://www.nhs.uk)

Choose the best answer for number 40:

Ở loài chim, diều được hình thành từ bộ phận nào của ống tiêu hóa?

Nội dung nào dưới đây không phải chức năng quản lí nhà nước về kinh tế?

Tai người bình thường có thể tiếp nhận thông tin nào dưới đây?

Phương pháp kí hiệu đường chuyển động dùng để biểu hiện các đối tượng địa lí: 

Read the following passage about taking selfies 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.

Căn cứ nào sau đây là một trong các căn cứ để phân loại vật nuôi

Cho tập hợp $B=\left\{x \in \mathbb{R} \, | \, (x^2 - 4).(x^2 + 25) = 0\right\}$. Tập hợp $B$ viết bằng cách liệt kê các phần tử là