关于光化学型烟雾事件发生的条件,描述正确的是()
A.夏秋季,早晨
B.气温高,中午,风速高
C.湿度低,天气晴朗
D.紫外线强,风速高
E.气温高,湿度高
参考答案:C
— Never thought to meet you here at this time.
— _____.[ ]
A. Glad to see you.
B. It's a small world.
C. So did I.
C. Oh, haven't you?
简述动车组配备有几个蓄电池?说出其主要作用?