炼铁工作者通常用生铁中的含()量来表示炉温。
A.Mn
B.S
C.Si
参考答案:C
Now that the forest was destroyed by a big fire, a large ________of trees ______ to be planted on the mountain.
A.number; has
B.quantity; has
C.amount; have
D.sum; have
变压器正常运行,变压器的温度达到稳定时的温升称为稳定温升。