This problem may lead to more serious ones if ____ unsolved.
we can not figure out ____quit a number of insects ,birds ,and animals are dying out .
He was chosen _________ of the company.
In the botanic garden we can find a(n)______of plants that range from tall trees to small flowers.
The experiment turned out to be ________, which wasn’t ______ they wanted.
She is in a poor ______of health, which worries her mother much.