1 . _____(bacterium) reproduce by dividing and making copies of themselves.  (所给词的适当形式填空)

2 . For example , pesticides can damage the land by killing not only harmful _______(bacterium) and insects , but also helpful ones . (所给词的适当形式填空)

3 . It has been discovered that ________(细菌) reproduce by dividing and making copies of themselves. (根据汉语提示单词拼写)

4 . Until now, it is still unknown to the scientists which _____ (细菌) causes the infection.（根据汉语意思填空）

5 . Each year, tens of thousands of people die because they are infected with antibiotic-resistant _______.

A．balconies

B．bandages

C．bacteria

D．banquets