No matter how far you have gone down the wrong road，________．（ ）
A．turn backB．turn offC．turn outD．turn over
________ great scientist Qian Xuesen is!
| A．How | B．How a | C．What | D．What a |
（）I think _______ necessary for you _______ breakfast.
| A．this; have | B．that; to have |
| C．it’s; to have | D．it’s; have |
The workers were made _____ the whole day.
| A．work | B．to work | C．worked | D．working |
He often plans_________ a very relaxing vacation.
A. having B. have C. to have
His father advised me _____ it again.
| A．try | B．trying | C．to trying | D．to try |