Question

　　To make an estimate means to guess the number of things in a group or guess a measurement of some kind. It sometimes means to make a calculation（计算）about the future, which is based not on exact data but on past experience. This kind of estimate has some basis, but it generally has to be changed and corrected later.

　　When you estimate a number, a size, a temperature or a weight, you do not count things one by one or use a measuring tool. You look at a group of things without counting them and try to get a rough, general idea of their number, you try to weigh something in your hand instead of on a balance. You feel hot and say“My temperature must be 38 degrees”or you look at a room and say that you estimate its area as 10×8 feet.

　　But in many situations in ordinary life we do not have time to measure things and must depend on estimates. Drivers do not have time to measure the distance between their own car and a car which is coming near. They must guess it; the guess or estimate will be based on their past experience. Experienced cooks do not trouble to measure the amount of salt they put into the soup or sugar they mix with flour.

　　 Suppose a man comes into the house and says“There are two inches of snow on the road”,his statement is only an estimate, but we believe it because we think that it is roughly correct. We put our boots on before we go into the snow.

　　For practical purposes in some situations it is safe to make estimates of quantity, but in other situations it is obviously dangerous. If it is your job to weigh drugs or make airplanes, do not depend on guessing but use an accurate instrument.

(1) In our daily life the estimate of a value or an amount is usually made ________.

[　　]

A．by further data

B．by instruments

C．by counting

D．according to one’s past experience

(2) According to the passage, measuring instruments are not always used in measuring things in everyday life because ________.

[　　]

A．people generally do not carry them along

B．it is more convenient to guess than to measure

C．they are not always ready when people need them

D．a general idea of things is-enough

(3) We can know from the man’s statement on snow that ________.

[　　]

A．he wants to inform people that it’s snowing heavily

B．it is necessary to depend on estimates

C．his estimate is quite exact

D．he has measured the level of the snow

(4) The writer thinks that depending on estimates ________.

[　　]

A．may save us both time and money

B．may bring us a sense of safety

C．does not always keep us out of danger

D．is practical but dangerous

Answer 1

答案：D;B;A;C
解析：

(1) D 短文第二句话给出答案。(2) B 根据文章中叙述的，人们在日常生活中，一些事情是不需要确切数据的，大体估计一下，这样要比用仪器去测量要方便得多。(3) A 短文倒数第二段说“这人说路上的雪有两英尺厚，他的说法只是估计，但我们相信是对的，因此在我们走进雪地前，穿上了靴子”，表示此人告诉人们雪下得很大。(4) C 最后一段中说“估计在一些情况下是安全的，在另一些情况下是危险的。”