In the process of drying certain kinds of fruits, sulphur fumes help ______.

A. predictable

B. unpredictable

C. changeable

D. unchangeable

A. reduced considerably

B. put a tick

C. examined carefully

D. motivated to develop

A. a kind of harmless animals

B. an achievement of human beings

C. a harmful factor to the environment

D. a kind of useful plants

A. expose foods to sun and wind

B. remove moisture from foods

C. produce pemmican

D. moisten foods

A. chamber

B. flat

C. area

D. studio

A. Environment pollution is real.

B. Reasons why low-lying areas are flooded.

C. Solutions to global warming.

D. Reasons why global warming is a problem.

A. A fifth of all the birds in the world live in the rainforest.

B. 20% of all the animals in the world live in the rainforest.

C. Nearly two million species of insects are found in the Amazon rainforest.

D. Nearly half of the world's species of plants grow there.