Experiments of this kind in both the U．S．and Europe well before the Second World War．
A．have conducted B．have been conducted
C．had conducted D．had been conducted
So _____ in the darkness that he didn't dare to move an inch.
A. he was frightened B. was he frightened C. frightened he was D. frightened was he
The police tried to get some clues from the suspect, but he remained______.
A．silent B．quiet C．calm D．secret
________by the advances in technology, many farmers have set up wind farms on their land.
A. Being encouraged B. Encouraging
C. Encouraged D.Having encouraged
Not until I began to work ____ how much time I had wasted.
A. didn't I realize B. did I realize C. I didn't realize D. I realized
It was_______ that they went for a drive in the countryside.
A. such a fine weather B. so fine a weather
C. such fine weather D. so fine weather
