1 . I hiked across other places _________ (empty) of their wildlife by human beings. （所给词的适当形式填空）

2 . ______ to go out alone, the retired president had to go for a walk with several bodyguards ______ him.

A．Having warned not …followed	B．Not having warned ... accompanied
C．Not warned ... following	D．Warned not... accompanying

3 . ______ red, the building stands out among the rest and looks very attractive.

A．Having painted

B．Paint

C．To be painted

D．Painted

4 . Diets are most effective if _______（将……和……结合）exercise. (根据汉语提示完成句子)

5 . So much carbon dioxide is ________ (排放) that it results in global warming. (根据汉语提示单词拼写)

6 . In certain licensed zoos, animal experts will make sure that the koalas ___________ (select) for each session are in a good state for human contact. (所给词的适当形式填空)

7 . Appropriate relaxation will get the students r____________, giving them enough motivation and energy to continue learning. (根据首字母单词拼写)

8 . Be careful when you deal with this chemical, as it will explode when        to sunlight.

A．being exposed

B．to expose

C．exposing

D．exposed

9 . According to a report ______（发布） by an environmental research group, about one billion live in unplanned settlements. （根据汉语提示单词拼写）

10 . ________ in 1636, Harvard is one of the most famous universities in the world.

A．To found

B． Founding

C．Founded

D．Having been founded