早稻是不宜连作的农作物，其原因是密度效应。 ( )
参考答案：错
A．To help him explain the information to his roommate.
B．To help him write a paper.
C．To prepare for a test.
D．To tell her if the notes are accurate.
康明斯发电车中，可以调整柴油机空载转速的是（）。
A.GAIN
B.SPEEDADJUST
C.RUNSPD
D.IDLESPD
