How long does it take you to finish your homework every day—I usually ________ two hours on it.

Engines are to machines ________ hearts are to animals

It’s the second time that I ________ to Shanghai.-What great changes！It’s ten years since I ________ it last time.[ ]

We can go in my car ______ you want to walk.

ecret of nature, they young scientisthas little time for entertainment.