搜题请搜索小程序“爱下问搜题”
问题 单项选择题

碱性焊条（如J506、J507）药皮中，除含CaF2外，还常含有一定量的碳酸盐，加热后分解出（），在高温时可与氢形成OH和HzO，同样具有防止氢气孔的作用。

A.CO

B.C02

C.HF

D.N2

答案

参考答案：B

填空题

阅读填词。根据短文内容和所给的首字母，写出文中各空缺单词的正确形式。

    It was the first time for most of us to be abroad (国外). So when we g  1   on the plane, we were very

e  2  .It took about nine h  3   to fly to London, but we didn't feel how long b  4   the service (服务) on the

plane was very good. We saw three English films. On the w  5   to the college (大学), we found very f  6   

people on the road but (除了) a lot of cars. We could see many buildings, green grass, forests and large

parking places. We lived in d  7   families and I lived in Mr Bank's. The Banks were very k  8   to me. They

have got a son n  9   Ben, and we soon became good f 10 .

1              2               3              4               5              

6              7               8              9               10             

查看答案
单项选择题

胶合板按使用树木分为落叶树材胶合板和( )。

A．夹心胶合板

B．复合胶合板

C．针叶树材胶合板

D．室内胶合板
查看答案