1 . Although ______ the suspect for two days, the officer didn’t attain any valuable information.

A．questioned	B．questioning
C．being questioned	D．having questioned

3 . You can spend three days ______ the rainforest with a local guide.

A．explore

B．to explore

C．exploring

D．explode

4 . The professor preferred ________lectures to students to ________ to attend meetings.

A．to give; invite

B．giving; inviting

C．to give; be invited

D．giving; being invited

5 . I live in the house with its door_________to the south.

A．facing

B．faces

C．faced

D．being faced

6 . _________a few activities successfully, Jackson becomes much more confident about himself and determines to be a host.

A．Organising	B．Having organised
C．Organised	D．To organise

7 . Our teacher often tells us that the present efforts ___ in our future will be rewarded sooner or later.

A．investing

B．to invest

C．being invested

D．invested

8 . ________ almost my entire professional life researching black holes, I finally came up with a better understanding of them.

A．Having spent

B．Spending

C．Spent

D．To spend

9 . ______ many failures, I have the courage to meet all challenges.

A．To experience

B．Having experienced

C．Experienced

D．Experiencing

10 . _________ from other continents for millions of years, Australia has many plants and animals not ________ in any other country in the world.

A．Having divided, to be found	B．Having been separated, found
C．Have been separated, found	D．Divided, finding