The theory he sticks to ______ to be of no use in our studies.
| A．proves | B．prove |
| C．proving | D．be proved |
He is leaving for Australia and it will be three years ________ he comes back.
| A．before | B．after | C．since | D．until |
The child was _______ after supper.
| A．enough tired to go to bed |
| B．too tired to go to bed |
| C．so tired that he went to bed |
| D．very tired, he went to bed |
Poor _____ it may be, there is no place like home, _____ you may go.
| A．as; wherever | B．though; whenever |
| C．in spite of; when | D．that; wherever |
_____ hard she tries, she can hardly avoid making mistakes in her homework.
| A．Much | B．However | C．As | D．Although |
When you read the book, you' d better make a mark _____ you have any questions.
| A．at which | B．at where |
| C．the place | D．where |