. Can you tell me the way you think of________ the problem?
| A．to work out | B．working out | C．work out | D．to work |
“Things________never come again！” I couldn’t help talking to myself.
| A．lost | B．losing |
| C．to lose | D．have lost |
Every one of us must know：________we live can we save the earth.
| A．by changing the way only |
| B．only by changing the way |
| C．by only changing the way |
| D．by changing only the way |
—Can those________at the back of the classroom hear me?
—No problem.
| A．seat | B．sit |
| C．seated | D．sat |
―Why? Where is my cellphone?
―Dear me! You _______ it in the taxi！
| A．have never left | B．never left |
| C．haven’t left | D．didn’t leave |
You need some facts _____ to base your theory.
| A．where | B．on which |
| C．in place where | D．in the place |