问题
选择题
It’s the gases ___ natural gas and the burning of coal give off ____ add to the overheating of the earth.
A．that; what
B．that; that
C．which; which
D．that; which
答案
答案：B
考查从句。第一个为定语从句，且先行词在定语从句中充当宾语，故用that或which；第二格是强调句的后半句，故用that。意为：是天然气和煤放出的气体增加了地球的过热。