90 % of the debts _______ so far.
| A．is paid back | B．have been paid off | C．has been paid off | D．are paid off |
—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 |
“What do you want to be？”asked Mrs.Crawford.“Oh, I________president，”said the boy, with a smile.
| A．have been | B．am |
| C．was | D．will be |