35. Sales of CDs have greatly increased since the early 1990s, when people_____ to enjoy the advantages of this new technology.
| A．begin | B．began | C．have begun | D．had begun |
－I looked after a group of fifteen French children, you know.
－That easy
| A．mustn’t be | B．mustn’t have been |
| C．can’t have been | D．can’t be |
The little boy was dirty from head to foot because of the tricks the other kids __on him.
| A．plays | B．played |
| C．had played | D．was playing |
We paddled over and climbed on to the steamboat, as quiet as mice.
| A．kept | B．keeping |
| C．to keep | D．keep |
Determined to try out “Happy Girls”, she from home without telling her parents.
| A．ran away | B．took away |
| C．kept away | D．put away |
To learn English well, we should find opportunities to hear English _____as much as we can.
| A．speak | B．speaking |
| C．spoken | D．to speak |