Lab workers must wear protective ______.
—Car prices have been going down sharply in the last 20 years.—It's not surprising because the law of market ________ the price of a product.
Is he the only one of the students who ________ here just now?
We ________ jump to conclusions before we have all the facts.
It was several years ________ I realized ________ David had lied to me.
The project will help people understand the many threats to the natural environment ________ endangered plants and animals live.