am÷an÷ap等于( )
A.am+n+p
B.am-n-p
C.am-n+p
D.an-m-p
am÷an÷ap=am-n-p.
故选B
Are you ______ now, Linda? If you're not, please help me cook dinner.[ ]
A. sure
B. busy
C. full
D. clean
《本地通信线路工程设计规范》YD5137-20053.2.4规定:光缆在承受允许张力或侧压力时,()不应变化。
A.光纤曲率半径
B.光纤衰减
C.光缆外形
D.光缆预留长度