金属氧化物避雷器内部（）直接影响产品质量，是引起其爆炸事故的主要原因。
参考答案：受潮
根据实际情况回答问题。
1. How many people are there in your family?
2. How many girls are there in your class?
3. How many boys are there in your class?
4. How many pens are there in your pencil-box?
5. How many books do you have?
下列植物中具有根，茎，叶的是 [ ]
A．海带
B．水绵
C．蔷薇
D．卷柏
