给出下列命题:

垂直于同一直线的两直线平行.

同平行于一平面的两直线平行.

同平行于一直线的两直线平行.

平面内不相交的两直线平行.

其中正确的命题个数是(    )

A．1

B．2

C．3

D．4

House prices keep rising these days. A flat in our city costs ____ now as in 1990.

A．as three times much

B．as much three times

C．much as three times

D．three times as much