问题
选择题
Many trees ________ along the streets every year. So the air is very fresh now.
A．plant
B．are planted
C．planted
D．were planted
答案
答案：B
句意：每年沿着大街都要种很多树。因此现在空气很清新。结合语境可知前文描述的是客观性的动作，故用一般现在时态。主语是动作对象，故用被动语态。选B。