题型:问答题 Though difficult, I _____ him find a job, which made him very pleased. [ ]A. tried to help B. managed to help C. tried helping D. succeeded to help 查看答案
题型:问答题 IEEE 802.3z系列标准中,使用波长为1300nm的单模光纤,传输距离可达到3000m的传输标准是( )。A.1000BASE-TB.1000BASE-CXC.1000BASE-LXD.1000BASE-SX 查看答案