托福（阅读）模拟试卷50
阅读题
DNA
DNA is an important means of fighting crime. Detectives use it to catch criminals. They use DNA found at a crime scene to determine the real murderer. This method is one of the most reliable ways to identify criminals.
DNA is a molecule that contains the blueprint for life. It controls how the body develops as it grows. It transfers the genetic traits of parents to their offspring. DNA is found in each of the 100 trillion cells of the human body. Each person has a set of DNA that is completely unique.
Investigators often find some traces of DNA at the crime scene or on the victim. There may be a piece of hair, a drop of blood, or even skin. The police can collect these samples to analyze them. With luck, they find a match between the sample and the suspect. Some factors may prevent them from succeeding, however. DNA samples could be contaminated. The sample may be mixed with someone else\’s, or it may be partially destroyed, by heat for example.
1.Which of the following best expresses the essential information in the highlighted sentence? Incorrect answer choices change the meaning in important ways or leave out essential information.
They use DNA found at a crime scene to determine the real murderer.(A)
A. DNA is used to figure out who the real murderer is.
B. DNA from the murderer is collected and studied.
C. The murderer uses DNA to tip off the investigators.
D. The crime scene has details of who the murderer is.
解析：
2.Which of the following best expresses the essential information in the highlighted sentence? Incorrect answer choices change the meaning in important ways or leave out essential information.
Each person has a set of DNA that is completely unique.(C)
A. The DNA each person has is common.
B. People’s DNA is unique to humans.
C. Every person has a unique set of DNA.
D. The DNA each person has is not unique.
解析：
3.Which of the following best expresses the essential information in the highlighted sentence? Incorrect answer choices change the meaning in important ways or leave out essential information.
The sample may be mixed with someone else’s, or it may be partially destroyed, by heat, for example.(A)
A. Someone’s DNA is useless if it is exposed to heat or mixed with someone else’s.
B. Heat and mixing are two ways to destroy DNA for an investigation.
C. The sample can contain heat and someone else’s DNA when mixed.
D. DNA can be mixed up with someone else’s as a way to destroy it.
解析：
Tornadoes
A tornado is a violent, rotating column of air. It reaches from a storm cloud to the ground. The most violent tornadoes are capable of huge damage. They can have wind speeds of 500km per hour. These twisters are very dangerous to life and property.
Tornadoes are most frequently found in the U.S., especially in the spring and summertime. Each year, 800 tornadoes are reported across the country. They result in 80 deaths and over 1,500 injuries. Paths of damage can be one mile wide and 50 miles long.
There is a region named \\
4.Which of the following best expresses the essential information in the highlighted sentence? Incorrect answer choices change the meaning i
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