People should send their complaints to the main office
=>Their complaints________________________.
A.
B.
C.
D.

The WWF had its operations in areas such as the preservation of _________ diversity, sustainable use of natural resources, the reduction of pollution, and climate change. (biology)
A.
B.
C.
D.

In 1986, the ______ changed its name to World Wide Fund for Nature to better reflect its activities. (organize)
A.
B.
C.
D.

________of oil will lead to the depletion of this natural resource.(exploit)
A.
B.
C.
D.

Noise pollution can cause stress and ______ and health problems for human.(psychology)
A.
B.
C.
D.

The air / many areas / so unclean that / people / have to / masks / going / streets
A.
B.
C.
D.

Industrial factories / throw / air / huge amounts / pollutant gases
A.
B.
C.
D.

Smoke / aircrafts / factory chimneys / bonfires / different kinds of vehicles / streets / many / other factors / damage / clean air / every day
A.
B.
C.
D.

One / biggest environmental impacts of human activities / air pollution
A.
B.
C.
D.

The trees in this area were                    off for crops and the construction of public facilities.
A.
B.
C.
D.