They have________signs in some places to remind (提醒)the visitors not to step on the grass.

It isn’t clear_____ is to blame.We need to find a solution to the problem first.

Scarcely _____ raining _____ the PLA fighters started on their way again.

t the Internet, those who are disabled _____ fewer avenues to meet people outside.

Some freshmen are finding it hard to ____ the new environment in the university.