RELAY是什么含义?
参考答案:
RELAY是继电器
—You look unhappy . What’s wrong ?
—I find ____ difficult ______on well with my classmates
A.it; to get
B.it ; getting
C.that ; to get
D.that ; getting
16Mn钢中的Mn的含量()。
A.≤1.0%
B.≤1.5%
C.≤2.0%
D.≤2.5%