[填空题]

A--seatbelt
B--landfill
C--acid rain
D---electrolytic treatment
E--industrial waste water
F--fly ash
G--greenbelt
H--ecological balance
I--global pollution
J--regional environment
K--shelterbelt
L--endangered species
M--the coastal windbreak
N--greenhouse effect
O---environmental pollution
P--sandstorm

（）酸雨（）生态平衡

[单项选择]When did it begin to rain
A. At about 6:00.
B. Before John got home.
C. After John reached home.

[填空题]results in "Acid rain" 71. ______
is already the 2nd largest source of electricity in the U. S. 72. ______
may give off more radiative pollution into the air than a nuclear plant 73. ______
can be taken only when large enough collector plates are built 74. ______
is the cleanest practical source of electricity 75. ______
costs 30% less than coal-fired power in France 76. ______
is less easy to subject to shortages caused by strikes and natural disasters 77. ______
is less threatened by international crises 78. ______
will not be considered as a supplement to conventional electricity for several decades 79. ______
could contribute to global warming 80. ______
Our demand for electricity is climbing so fas