We’d better _________ when he is thinking, as he prefers to solve problems on his own.
| A．wake him up | B．set him aside |
| C．leave him alone | D．ring him up |
—Oh no! We're too late.The train________.
— That's OK.We'll catch the next train to London.
| A．was leaving | B．had left |
| C．has left | D．has been leaving |
—Could I use your car tomorrow morning?
—Sure.I________a report at home.
| A．will be writing | B．will have written |
| C．have written | D．have been writing |
Generally，students' inner motivation with high expectations from others________essential to their development.
| A．is | B．are | C．was | D．were |
—I don't understand why you didn't go to the lecture yesterday afternoon.
—I'm so sorry.But I________my homework.
| A．had done | B．was doing | C．would do | D．am doing |
If nothing________，the oceans will turn into fish deserts.
| A．does | B．had been done |
| C．will do | D．is done |