RH处理钢水()最易受侵蚀。
A.真空室顶部
B.真空室底部
C.插入管
参考答案:C
In 1942, Columbus and his crew arrived ________ was so-called the New World by the westerners.
A.what
B.in which
C.where
D.in what
在消防中控室的防火巡查中,发现()应现场改正。