Học tại trường Chưa có thông tin
Đến từ Phú Yên , Chưa có thông tin
Số lượng câu hỏi 51
Số lượng câu trả lời 488
Điểm GP 27
Điểm SP 260

Người theo dõi (57)

sieu pham zed
Đỗ Đình Hưng
$Mr.VôDanh$
BioLOgYPro

Đang theo dõi (187)

Mỹ Duyên
Pakiyo Yuuma
Đỗ Thanh Hải
Quìn

Không Tên

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.

        The main cause of tooth decay is acid, which is produced by bacteria in the mouth. The acid removes minerals from tooth enamel, allowing tooth decay to begin; the saliva in your mouth encourages remineralization and neutralizes the acid. The rate at which bacteria in the mouth produce acid depends on the amount of plaque on the teeth, the composition of the microbial flora, and whether the bacteria of the plaque have been “primed” by frequent exposure to sugar. To keep your teeth healthy, a regular dental hygiene program should be followed.

        Removing plaque with a toothbrush and dental floss temporarily reduces the numbers of bacteria in the mouth and thus reduces tooth decay. It also makes the surfaces of the teeth more accessible, enabling saliva to neutralize acid and remineralize lesions. If fluoride is present in drinking water when teeth are forming, some fluoride is incorporated into the enamel of the teeth, making them more resistant to attack by acid. Fluoride toothpaste seems to act in another way, by promoting the remineralization of early carious lesions.

                   In addition to a regular dental hygiene program, a good way to keep your teeth healthy is to reduce your intake of sweet food. The least cavity-causing way to eat sweets is to have them with meals and not between. The number of times you eat sweets rather than the total amount determines how much harmful acid the bacteria in your saliva produce. But the amount of sweets influences the quality of your saliva. Avoid, if you can, sticky sweets that stay in your mouth a long time. Also try to brush and floss your teeth after eating sugary foods. Even rinsing your mouth with water is effective. Whenever possible, eat foods with fiber, such as raw carrot sticks, apples, celery sticks, etc., that scrape off plaque, acting as a toothbrush. Cavities can be greatly reduced if these rules are followed when eating sweets.

We can infer from the passage that one benefit of fluoride to healthy teeth is _________ .

A. It strengthens tooth enamel

B. It stimulates saliva production

C. It makes teeth whiter

D. It is a replacement for brushing and flossing in dental care

Không Tên

Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions from 43 to 50.

New surveys suggest that the technological tools we use to make our lives easier are killing our leisure time. We are working longer hours, taking fewer and shorter vacations (and when we do go away, we take our cell phones, PDAs, and laptops along). And, we are more stressed than ever as increased use of e-mail, voice mail, cell phones, and the Internet is destroying any idea of privacy and leisure.

Since the Industrial Revolution, people have assumed that new labor-saving devices would free them from the burdens of the workplace and give them more time to grow intellectually, creatively, and socially - exploring the arts, keeping up with current events, spending more time with friends and family, and even just "goofing off".

But here we are at the start of the 21st century, enjoying one of the greatest technological boom times in human history, and nothing could be further from the truth. The very tools that were supposed to liberate us have bound us to our work and study in ways that were inconceivable just a few years ago. It would seem that technology almost never does what we expect.

In “the old days”, the lines between work and leisure time were markedly clearer. People left their offices at a predictable time, were often completely disconnected from and out of touch with their jobs as they traveled to and from work, and were off-duty once they were home. That is no longer true. In today's highly competitive job market, employers demand increased productivity, expecting workers to put in longer hours and to keep in touch almost constantly via fax, cell phones, e-mail, or other communications devices. As a result, employees feel the need to check in on what is going on at the office, even on days off. They feel pressured to work after hours just to catch up on everything they have to do. Workers work harder and longer, change their work tasks more frequently, and have more and more reasons to worry about job security.

Bosses, colleagues, family members, lovers, and friends expect instant responses to voice mail and e-mail messages. Even college students have become bound to their desks by an environment in which faculty, friends, and other members of the college community increasingly do their work online. Studies of time spent on instant messaging services would probably show staggering use.

This is not what technology was supposed to be doing for us. New technologies, from genetic research to the Internet, offer all sorts of benefits and opportunities. But, when new tools make life more difficult and stressful rather than easier and more meaningful - and we are, as a society, barely conscious of it - then something has gone seriously awry, both with our expectations for technology and our understanding of how it should benefit us.

(From "Summit 1" by Joan Saslow & Allen Ascher)

Question 46: It can be inferred from the fourth paragraph that ___________.

A. life is more relaxing with cell phones and other technological devices

B. employers are more demanding and have efficient means to monitor employees

C. it is compulsory that employees go to the office, even on days off

D. employees have more freedom to decide what time they start and finish work