通过用干湿计测量裸地、草地和茂密灌木丛的湿度,可以探究[ ]
A.植物对水的需要量
B.空气温度对植被类型的影响
C.植物对空气湿度的影响
D.不同植被类型对空气温度的影响
答案:C
“维规”规定ZPW-2000A型无绝缘轨道电路在调整状态时,“轨出1”电压应不小于多少?
—Could you tell me _________ last night?
—Er, I was watching TV at home.[ ]
A. what you were doing
B. what were you doing
C. what you are doing
D. what are you doing