The research laboratory is going to ______ the new type of computer to use.

—Look! He's running so fast! —Hard to ______ his legs w...

单项选择题—Look! He's running so fast!
—Hard to ______ his legs were once broken.

Have a cigarette, ______A．will youB．don't youC．do youD．...

单项选择题Have a cigarette, ______

The moment I got home, I found I ______ my jacket on th...

单项选择题The moment I got home, I found I ______ my jacket on the playground.