阅读理解
"In only six days I lost seven pounds of weight."
"Two full inches in the first three days!"
These are the kinds of statements used in magazine, newspaper, radio and television ads, promising
new shapes and new looks to those who buy the medicine or the device.The promoters of products say
they can shape the legs, slim the face, smooth wrinkles, or in some other way to add to beauty or
desirability.
Often such products are nothing more than moneymaking things for their promoters.The results they
produce are questionable, and some are dangerous to health.
To understand how these products can be legally promoted to the public, it is necessary to
understand something of the laws covering their regulation.If the product is a drug, FDA(Food and Drug
Administration)can require proof under the Food, Drug, and Cosmetic Act that is safe and effective
before it is put on the market.But if the product is a device, FDA has no authority to require premarketing proof of safety or effectiveness.If a product already on the market is a danger to health, FDA can request
the producer or distributor to remove it from the market voluntarily, or it can take legal action, including
seizure(查封)of the product.
One notable case a few years ago involved an electrical device called the Relaxacisor, which had
been sold for reducing the waistline.The Relaxacisor produced electrical shocks to the body through
contact pads.FDA took legal action against the distributor to stop the sale of the device on the grounds
that it was dangerous to health and life.
Obviously, most of the devices on the market have never been the subject of court proceedings(法律
诉讼), and new devices appear continually.Before buying, it is up to the consumer to judge the safety or
effectiveness of such items.
1. It can be inferred that the ads mentioned in the text are________.
A. objective
B. costly
C. unreliable
D. illegal
2.Which of the following is TRUE according to the text?
A. The court is in charge of removing dangerous products.
B. New products are more likely to be questionable.
C. The production of a device must be approved by FDA.
D. The promoters usually just care about profits.
3. FDA can ask for the proof of safety and effectiveness of a product________.
A. if it is a drug
B. if it is a device
C. if its consumers make complaints
D. if its distributors challenge FDA's authority
4. The Relaxacisor is mentioned as________.
A. a product which was designed to produce electricity
B. a product whose distributor was involved in a legal case
C. a successful advertisement of a beauty product
D. an example of a quality beauty product
可知R总在减小，由此可推知传感器的电阻在变小，再由S与R、M的分压关系可讨论出R的大小对U的影响。