弹簧式固定义齿杆的材料应具有的机械性能包括()

A．受力时不变形

B．受力时不折断

C．具有一定的弹性

D．具有一定的抗腐蚀性

E．具有一定的生物相容性

The house rent is expensive. I've got about half the space I had at home and I'm paying _____ here. [ ]

A. as three times much

B. as much three times

C. much as three times

D. three times as much