若频率为0.2，总数为100，则频数为（　　）

近几年来，我国在载人航天、探月工程、载人深潜、北斗卫星导航系统，超能计算机，高速铁路等方面分别取得了重大突破，同时，第一艘航母“辽宁舰”入列，歼—15战机顺利进行了起降航母的飞行训练……上述成就表明我国【      】 

根据短文内容，判断正确还是错误。

    There is a big fruit shop near Kitty's home. Kitty is at the fruit shop now. There are many kinds of fruits. There are big apples, yellow pears, fresh bananas, juicy oranges, and so on. Kitty wants to buy some apples and bananas. They are expensive. The apples cost ten yuan. The bananas cost twenty yuan.

人体呼出的气体中二氧化碳含量增多了，这些二氧化碳产生于（　　）