Not until I began to work ________ how much time I had wasted.
| A．didn’t realize | B．did I realize | C．I didn’t realize | D．I realized |
A few _____ looked at him curiously when he suddenly stopped and burst out crying.
| A．passers-by | B．passer-bys |
| C．passers-bys | D．passer-by |
Changbai Mountain is one of China’s largest nature reserves, and has many ____ plants and animals.
| A．various | B．rare | C．major | D．common |
Mrs. Green went back home hurriedly, where her two little twins were crying, _____ they were hungry.
| A．said | B．saying | C．to say | D．having said |
Parents have a duty to ____ their children from the harmful effects of the Internet.
| A．hide | B．prevent | C．stop | D．protect |
Qiandao Lake, widely known ______ a tourist site, is famous _____ its clear and drinkable water.
| A．as; to | B．for; as | C．for; to | D．as; for |