根据《通信建设工程安全生产操作规范》,利用挖掘机开挖沟槽,行驶时,铲斗应离地面1m左右,上下坡时其坡度不应超过()。
A.15°
B.20°
C.25°
D.30°
参考答案:B
石斛除益胃生津、滋阴除热外,还能()
A.凉血止血
B.明目强腰
C.软坚散结
D.清心除烦
E.祛痰益气
New functions ____to the phones at present by scientists.[ ]
A. is being added
B. are added
C. are being added
D. is added