安全技术一般分为（）

A、直接安全技术

B、间接安全技术

C、基础安全技术 

D、高级安全技术

E、指示性安全技术

A client has sustained a right tibial fracture and has just had a cast applied. Which instruction should the nurse provide in his cast care

A．Cover the cast with a blanket until the cast dries.

B．Keep your right leg elevated above heart level.

C．Use a knitting needle to scratch itches inside the cast.

D．A foul smell from the cast is normal.