Ecosystems regulate the climate, determine the composition of the atmosphere, make new soil, controlling diseases, and provide food.

_______ the room been cleaned yet?

All of them hope that everything will be ready in _______

Peter was the last person _______

_______ flower gets its smell from _______ oil that the plant produces.

I have just bought a cottage by _______

Peter went _______ the man and asked him the best way to get _______ town.

“_______,” the doctor advised his patient.

The audience were very _______ by her _______.

_______ the question asked by the campus authorities.

Scientists have not been able to cure AIDS, _______ any vaccine against the disease.

Barbara asked me _______ her homework that afternoon.

You _______ to do the homework or the teacher will punish you.

National Parks are usually located in places where have been largely undeveloped, and are often with exceptional native animals, plants, and unusual geological features.

Oceans, that cover about 70% of the Earth’s surface, contain approximately 97% of the Earth’s water supply.

Peter was not always so hopeless.