There are over 58000 rocky objects in ______space，about 900 of which could fall down onto ______ earth.

found the homework was not so heavy as ______ I ______ to get in my old school.

We must our pets. They’re our friends.

Despite the failure to save every endangered species, we may __________ the majority from extinction.

The food smells ________, so do not eat it any more, Jack.