在钢中含少量的不到()的钒,能改善钢的焊接性能,增加钢的热强性和对蠕变的抗力。
A、0.3%
B、0.4%
C、0.5%
D、10%
参考答案:C
In recent years, TCP/IP has also begun to be used by telephone companies to provide faster, cheaper telephone (67)
A.transmitting
B.transmited
C.transfers
D.transmissions