— ______ was your trip to Mount Emei, Alice?一 It was great! We really had a good time there.
A:When
B:What
C:Where
D:How
氢氧燃料电池用于航天飞船,电极反应产生的水,经冷凝后可作为航天员的饮用水,其电极反应如下:①2H2+4OH﹣-4e﹣=4H2O,②O2+2H2O+4e﹣=4OH﹣ 当得到1.8L饮用水时,电池内转移的电子数约为( )
指出下列四条食物链中,正确的是( )
—______. I need a bag.
下列各句中,没有语病的一项是( )