A NASA experimental jet , the X-43A,flew at a world –record speed ---11,260 kilometres an hour on November 17.This speed is __ as that of sound.
| A．astentimesfast | B．tentimessofast | C．tentimesasfast | D．tentimesfaster |
It’s reported that some wild animals were found in a big cave in the mountain.
| A．to hide dead | B．hidden dead | C．hiding dead | D．hidden death |
Some researchers are finding that daydreaming may be important to mental health .Daydreaming ,they say, is good means of relaxation.
| A．the; ／ | B．／; the | C．／; ／ | D．／; a |
—I am so angry that I could blow my top!
—Oh, dear, _______． What’s wrong?
| A．no hurry | B．no wonder | C．take it easy | D．take your time |
Some scientists believe that it won’t be long _______ robots are widely used in all walks of life．
| A．since | B．after | C．before | D．until |
Under no circumstances _______ the difficulties when they were on an expedition to the Antarctic．
| A．they gave way to | B．did they give way to |
| C．they had given way to | D．had they given way to |