一个30°的角在10倍的放大镜下看是（ ），一条5cm长的线段在10倍的放大镜下看是（ ）cm。
30°；50
It was ______ the old clock that the old man spent the whole morning at home.
A．repairing
B．repaired
C．to repair
D．in repair
组织培养
