The doctor said jokingly that his own infection of the virus _______ the discovery of a vaccine (疫苗)of the disease.
| A．stood for | B．called for | C．paid for | D．contributed to |
However, even on TV and the radio you will hear differences in the way ______ people speak.
| A．that | B．in which | C．/ | D．all of the above |
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 |