冷却水中除含有悬浮物外,还有一定数量的()。
参考答案:钙、镁盐
In the Direct Method,teachers encourage learners to ______ rules of grammar through active use of the target language in the classroom.
A.apply
B.analyze
C.induce
D.paraphrase
火电厂过程控制方式可以分为哪几种?