【判断题】当有火灾发生时,手动报警按钮的动作信号作为自动联动触发信号,控制消防水泵的启动。()
【单选题】已知函数f(x)=ax 2 +2ax+4(a>0),若x 1 <x 2 ,x 1 +x 2 =0,则( )
D.
f(x 1 )与f(x 2 )的大小不能确定
【单选题】蓝靛染色主要用浸染方法,浸染温度一般为 ( ) 。
【判断题】椎动脉三角是介于颈长肌、前斜角肌和锁骨下动脉第一段之间的区域
【单选题】What do you understand from the man's answer?
A.
He enjoys writing home every week.
B.
He never writes home once a week,
C.
He doesn't write home once a week now.