钨极氩弧焊比较好的引弧方法有高频振荡器引弧和高压脉冲引弧。( )
参考答案：对
用所给单词的适当形式填空。
1. The boy is doing ______________ (he) homework.
2. How many ______________ (ticket) do you want to buy?
3. I am ______________ (tall) than my little brother.
4. Li Ming ______________ (have) two pairs of socks.
5. She is ______________ (get) ready for bed.
货币市场基金可以投资于（）。
A．股票
B．可转换债券
C．信用等级在AAA级以下的企业债券
D．剩余期限在397天以内的债券
