We all agree that _______ good knowledge of physics is a must in explaining such _______ natural phenomena.
| A．a; / | B．a; a | C．/; a | D．/; / |
Many people believe the English _______ on TV and the radio is standard English.
| A．speaking | B．speak | C．spoken | D．is spoken |
It was because of the bad weather __________ the football match had to be put off.(推迟)
| A．so | B．so that | C．why | D．that |
It is the first time that I _______ this kind of moon cake.
| A．enjoyed | B．have enjoyed | C．enjoy | D．enjoying |
There was ______ time _____ Chinese used foreign oil.
| A．a; when | B．a; while | C．/; when | D．/; while |
While ___ along the street, I met an old friend of mine.
| A．I walking | B．was walking | C．I am walking | D．walking |