Some people argue that using _____ nature to meet our own needs may spell disaster, unless we start to look around and understand how ______ clean environment benefits us all.
| A．/; a | B．the; / |
| C．the; a | D．a; a |
By the time Jack returned home from America, his son __________ from college.
| A．graduate | B．has graduated | C．had graduated | D．had been graduated |
She was good at physics _________she found it boring.
| A．despite | B．in spite of |
| C．in spite the fact that | D．despite the fact that |
The experiment show that proper amount of exercise, if ________ regularly, can improve our health.
| A．carry out | B．carried out | C．to carry out | D．being carried out |
Listen! Do you hear someone _________ for help?
| A．call | B．calling | C．to call | D．called |
His first book ________ next month is based on a true story.
| A．published | B．to publish | C．to be published | D．being published |