问题

Now more and more people have come to know the role that trees _____in our natural environment. [ ]

A: do
B: take
C: play
D: work

正确答案是：

同类题型

John opened the door There_______ he had never seenbefore

The hair band isn’t _______. It belongs to _______.

Though many extra planes and trains are used to carry passengers, traffic tools are still _____ neededduring “May Day” holidays [ ]

Internet shopping will ready whenpeople make sure that it is safe

On the bus, all the people except the driver ______ to talk and laugh during the journey.