The sun must be made of lighter stuff than the earth. If the earth were______, it would weigh four times as much. A．bigger B．smaller C．as bigger D．as big as the sun
A. A．bigger B．smaller C．as B.as
【参考答案】
D 本题考查形容词的比较级，根据题意，太阳一定是由比地球轻的物质构成的，如果地球和太阳一样大，它会是太阳四倍那么......