铁-镍蓄电池放电和充电时发生的反应为：Fe+NiO₂+2H₂O 

A．放电时铁为负极

B．充电时阴极的电极反应式为：Ni（OH）₂-2e^-=NiO₂+2H⁺

C．放电时NiO₂的反应为：NiO₂+2H₂O+2e^-=Ni（OH）₂+2OH^-

D．蓄电池的电极必须浸在碱性电解质溶液中

从括号中选出适当的词填空。  

1.  We need______  (health/healthy)  food   every day.

2.  I have an egg, an apple and an ice cream ______( for /and)  breakfast.

3.  Liu Xiang is a great ______ (running/run) star.

4.  For dinner, he likes  ______ (carrots/carrot) and salad.

5. It's important to eat______ (good/well) for  runners.