I was surprised to find the snack shops around the school empty; the students everything!
| A．had been buying | B．had bought |
| C．have bought | D．have been buying |
Not everyone has realized what_______ important part the balance of________ nature plays in their life.
| A．an；the | B．/；the | C．an；/ | D．the；/ |
It’s easier to catch a _____ lion than the one that’s awake.
| A．sleep | B．slept | C．sleeping | D．to sleep |
Mr. Smith didn’t go to the party because he had a lot of experiments _____.
| A．do | B．did | C．done | D．to do |
Only if he gets a job ______ have enough money to build his own house.
| A．he can | B．can he | C．he will | D．did he |
Harry _______ golf after graduation from college.
| A．took up | B．took in | C．took over | D．took down |