下列物质中属于电解质的是（）。A.CO2 B.NH3 C.NaCl D.C2H5OH
When I got off the bus, I found my pocket and the money gone. A．picked B．stolen C．missing D．lost
Lucy fell asleep_______ she was listening to music.A．beforeB．whileC．afterD．as soon as
小麦的叶肉细胞通过光合作用合成葡萄糖，组成葡萄糖的碳、氢和氧三种元素分别来自 A．、和 B．、和 C．、和
命题甲：动点P到两定点A、B的距离之和|PA|+|PB|=2a(a＞0，常数)；命题乙:P点轨迹是以两定点A、B为焦点的椭圆.则命题甲是命题乙的( ) A.充分不必要条
The earthquake and the suffering has caused will affect us greatly for a long time. A.that B.it C.which D.what
Technology today has stolen away our voices and robbed our children of memories. I’ve been keeping count of how often people sing around the house these days. The fact is, they don’t. My ea
已知函数，，则是 A．奇函数且在上单调递增 B．奇函数且在上单调递减 C．偶函数且在上单调递增 D．偶函数且在上单调递减
