______ the help of my teachers, I improve my English. [ ]
A. Of
B. With
C. Under
D. To
答案:B
光纤布放时不得受压,不能把光纤折成直角,需拐弯时应弯成圆弧,圆弧的直径不小于()mm,光纤应理顺绑扎。
A.60
B.70
C.80
D.90