The computer system_______suddenly while he was searching for information on the Internet.
| A．broke down | B．broke out | C．broke up | D．broke in |
Not until the early years of the 19th century _____ what heat is.
| A．man did know | B．man knew | C．didn’t man know | D．did man know |
_____ food is stored deep in the tunnel for the use of war.
| A．A great many | B．A large number of | C．Scores of | D．A large amount of |
____ she couldn’t understand was _____ fewer and fewer students showed interest in her lessons.
| A．What; why | B．That; what | C．What; because | D．Why; that |
She looks forward every spring to ____ the flower-lined garden.
| A．visit | B．paying a visit | C．walk in | D．walking in |
It is not socially ______ for parents to leave children unattended at that age.
| A．accessible | B．acceptable | C．adorable | D．adaptable |