He started to work dilligently _____ he came up with the idea of hybrid rice for the first time in the 1960’s.
| A．at once | B．the moment | C．for the moment | D．in no time |
The population of the province to more than twice what it was in 1949. The figure is now approaching 74 million.
| A．are growing | B．have grown | C．grew | D．has grown |
I asked for some more cake, but there was left.
| A．no one | B．none | C．a little | D．a few |
—Is it OK to take this seat?
—Sorry, .
| A．it’s taken | B．take it | C．here you are | D．never mind |
-I didn't go to the art show, because I lost my ticket．
-You______have borrowed mine I didn't go to see it anyway
| A．would | B．need | C．could | D．must |
Birds'singing is sometimes a warning to other birds________away.
| A．staying | B．stayed | C．stay | D．to stay |