【题目】Today there are more airplanes________ more people than ever before in the skies.
A.carry
B.carrying
C.carried
D.to be carrying

【答案】B
【解析】句意：现在比以前有有更多的飞机运送乘客。此处airplane和carrying之间是主动关系，故用现在分词作定语。故选B。