Many scientists believe that the universe began with an enormous explosion called the “Big Bang”, ______ happened about 13.7 billion years ago.
| A．that | B．which | C．when | D．what |
We don't imagine the twins have arrived, _____?
| A．do we | B．have they |
| C．don’t we | D．haven’t they |
Mother said that Mike could eat two of ten oranges and that the rest _______ left for Tom and Betty.
| A．were | B．was | C．be | D．being |
One-third of the country _____ covered with trees and the majority of the citizens _____ black people.
| A．is; are | B．is; is |
| C．are; are | D．are; is |
You look so young．Haven’t you graduated from your university?
Yes, I _______ in the English Department of Zhejiang Normal University for four years．
| A．was studying | B．study |
| C．had studied | D．studied |
All the scientific evidence ______ that increasing use of chemicals in farming______damaging our health．
| A．show; are | B．shows; are |
| C．show; is | D．shows; is |