He has made a discovery, _________ of great importance to the progress of science and technology．
A．I think which is B．which I think is
C．which I think it D．which I think it is
Rosy came in for _________ coffee and told me _________ firecrackers outside kept her awake last night．
A．a; the B．不填; the
C．the; a D．a; the
—Dad, where on earth did you put my raincoat?
—Oh, Jim．I forgot to tell you．It _________ behind your bedroom door．
A．would hang B．has hung
C．is hanging D．hung
In autumn, _________ the weather is often cool and fine, people living in the city always like climbing hills for outdoor activities to strengthen their health．
A．which B．where C．as D．when
—I telephoned him twice and I couldn’t get through to him．
—The line might have been out of order, _________?
A．don’t you B．do you
C．wasn’t it D．hadn’t it
The USA has a quarter of the leading 200 in the latest ranking of the world universities, _________ 30 of the universities are in the UK．
A．when B．while C．where D．why
