Edison was a clever boy, and ______ he was fourteen, he had learned advance mathematics by himself.
A．whenever B．by the time C．the moment D．ever since
I ______ to go on a diet, but the dishes at the party were simply impossible to resist.
A．had intended B．am intending C．intend D．could intend
Not until the teacher explained the importance of getting up early ______ we promise to come early.
A．should B．would C．did D．could
—How about the party ______ at Mary’s house?
—Wonderful! Everyone had a good time．
A．holding B．to hold C．being held D．held
This is the best way ______ I have thought of ______ the problem.
A．that; solving B．in which; solving
C．which; to solve D．/; to solve
Particular attention must be paid ______ welfare, especially in the poor area.
A．develop B．to develop C．to developing D．developing
