Question 9
Agricultural runoff is polluting the Chang Jiang in China. What effect does the flow of large amounts of fertilizer and sewage have on the river?
A
It encourages germs to grow in the river, causing people and animals that drink the river water to become sick.

B
It causes large plants to grow thickly along the shore of the river, preventing animals and people from accessing the river.

C
It settles on the river bottom in thick, sludgy layers, making the river too shallow for commercial and recreational boats to navigate.

D
It causes algae and plants to grow and cover the surface of the water, blocking sunlight and killing plants and animals that live underneath.