Scientists say it may be five or six years _______ it is possible to test this medicine on human patients.
| A．since | B．after | C．before | D．when |
He’s feeling rather _______ with himself after the examination.
| A．pleasing | B．pleased | C．pleasant | D．pleasurable |
In that big fire all their houses were__________, so they had to build new ones.
| A．hurt | B． harmed | C．injured | D． destroyed |
They showed me a medicine that was scientifically ______ from human hair and used in helping their growth.
| A．learned | B．chosen | C．prepared | D．separated |
It is said that there are millions of camels in India and _______ of them is growing.
| A．the number | B．a great number | C．a lot | D．a good many |
It was on a cold winter evening_______ his father left home and was never back.
| A．where | B．which | C．that | D．when |