提取公积金偿还公积金贷款本息提取时间有限制吗？一年可以提取几次？

带式除铁器有哪两种运行方式？

为什么要对电子式电能表进行高频电磁场抗扰度试验？

吹炼低磷铁水时，铁水中（）元素的供热量最多。

A.碳

B.磷

C.铁

Although the parties are entitled to make their contract in any manner that they like，it is usual for them to adopt one of the standard forms and then（）it as they think fit.

A.amend

B.repair

C.improve

D.clear

判断某洋流性质为寒（暖）流，判断理由是什么？