People have lots of problems living in the central Australian desert, ____ the lack of water is the most serious one.
| A．of which | B．which | C．for which | D．where |
He is a successful businessman and he ___ his success more to luck than to ability.
| A．attaches | B．adapts |
| C．owes | D．fastens |
__________is no possibility __________Bob can win the first prize in the match.
| A．There；that | B．It；that |
| C．There；whether | D．It；whether |
The police recommended parents __________their children under 12 to ride to school for safety.
| A．not allow | B．do not allow |
| C．mustn’t allow | D．couldn’t allow |
----I wonder why Jane looks worried today.
----I’m not sure, but she a small accident driving here.
| A．could have | B．might have |
| C．might have had | D．should have had |
We tried ______ to persuade him to stay home, but at last, he went to the construction site despite his bad illness.
| A．in case | B．in vain |
| C．in fact | D．in addition |