A:2H2O=2H2+O2↑
B:4Fe(OH)2+O2+2H2O=4Fe(OH)3
C:2F2+2H2O=4HF+O2
D:2Al+2NaOH+2H2O=2NaAlO2+3H2↑
我们把尺子压弯、把橡皮筋拉长时,可以感受到它们对手有力的作用。物体由于发生____ 而产生的力叫做弹力。
下列属于我国特产珍稀动物的是( )
当遇到别人突发紧急情况时,应力所能及的予以救助,下列做法不恰当的是( )
——Though radio and television are ____ popular in the world today, I think the TV is ____ useful.——Of course, on TV we can see and hear what is going on home and abroad.