It is not always easy for the public to see _____ use a new invention can be of to human life.
| A．whose |
| B．what |
| C．which |
| D．that |
Into the dark apartment _______, who was quite surprised when everyone shouted “Happy Birthday”.
| A．did David walk | B．David walked | C．David did walk | D．walked David |
Sorry I’m so late, but you cannot imagine _______ great trouble I took to find your house.
| A．what | B．how | C．which | D．why |
I’m going to buy my daughter another interesting novel, _______ she would like to read．
| A．that | B．what | C．one | D．it |
_______ playing dumb with teachers．They know very well their students.
| A．It’s no use | B．There’s no doubt | C．It’s no wonder | D．There’s no need |
— I heard the phone ringing in the office next door.
— You _______ it. They haven’t got a phone yet.
| A．couldn’t hear | B．couldn’t have heard | C．didn’t hear | D．wouldn’t have heard |