What can be concluded from the passage

A．Genuine writers often find their work interesting and rewarding.

B．A writer's success depends on luck rather than on effort.

C．Famous writers usually live in poverty and isolation.

D．The chances for a writer to become successful are small.

单向通道保护环带一条链的拓扑结构，在环上光纤中断时，环上除交叉点外的站到链上业务（）保护。

A、可以

B、不可以