问题 解答题
下面是中心小学六(1)班第一小组女生的身高记录单.
编号1234567
身高(cm)142143140154145144168
(1)这组女生身高的平均数是多少?中位数呢?
(2)你认为是用平均数还是用中位数代表这组女生的身高比较合适?
答案

平均数是:

(142+143+140+154+145+144+168)÷7

=148;

中位数:这7个数按照从小到大的顺序排列为:

140,142,143,144,145,154,168;

最中间的数是144,所以中位数是144.

答:平均数是148,中位数是144.

(2)在这组数据中有两个特别大的数154,168,这使的平均数比较大,所以使用中位数代表这组女生的身高比较合适.

答:使用中位数代表这组女生的身高比较合适.

单项选择题
阅读理解

You know that pearls grow inside oysters(牡蛎), but would you ever think to look for diamonds inside an ostrich(鸵鸟)? Well, a hunter once shot an ostrich and discovered, to his great surprise, that the big bird had swallowed a bunch of diamonds. How could such a strange thing happen?

Like many other birds, the ostrich swallows small stones that stay inside its “gizzard”. The gizzard is a bird’s second stomach. It is where the food is ground up. The small stones help to grind up the food so it can be digested. The small stones do the chewing because birds don’t have teeth. In that case of the ostrich with the diamonds, the bird simply had expensive taste in rocks. It used the diamonds to digest its dinner.

Diamonds and stones aren’t all that an ostrich will swallow. If there are no stones around, it will eat just about anything. Sadly for ostriches in zoos, this can be a fatal habit. The tendency to swallow anything it sees has caused the death of many an ostrich. Cruel or careless people often throw things into the bird’s living space. They throw keys, coins, and even large objects such as horseshoes. The ostrich swallows them without hesitation. Coins can be the worst. Inside the ostrich they wear down to a razor-sharp edge. They will cut open the bird’s gizzard from the inside. When one young zoo ostrich died, 484 coins weighing more than eight pounds were found in its gizzard.

小题1:

Which of the following best expresses the main idea of the passage?

A.Birds often eat strange and funny things.

B.Ostriches will swallow anything to help them digest food.

C.One ostrich died with 484 coins in its gizzard.

D.Ostriches are often hurt by cruel or careless people.小题2:

The ostrich is not smart enough to ______.

A.digest its own food

B.eat only diamonds

C.avoid eating harmful objects

D.escape from the zoo小题3:

The sentence “the small stones do the chewing” makes rocks seem as though they were ______.

A.important

B.alive

C.dangerous

D.uncomfortable小题4:

he word “fatal” in the third paragraph is another word for “______”.

A.foolish

B.careless

C.deadly

D.cruel