如图所示,与照相机相比较,眼睛的神奇之处是
A.视网膜类似于胶片
B.晶状体类似于镜头
C.晶状体焦距可调节
D.视网膜上成缩小的像
答案:C
Nearly half of the houses in Britain are owned by the people who live in them. About 1/3 are owned by the local authorities and the rest are rented from private owners.
SDH设备可以配置成TM网元,它的特点是()。
A、所有光方向到TM的业务必须落地
B、只能有一个光方向
C、不能光方向的业务不能通过光板直接穿通
D、光板的最高速率必须低于622M