气焊时的起焊点都应选择在定位点上。
参考答案：错
The workers have produced _______ this year as they did two years ago.
A．astwicemuchcotton
B．twiceasmuchcotton
C．twicecottonasmuch
D．cottontwiceasmuch
变压器的一、二次侧的漏阻抗Z1和Z2是常数
