有关MR血管造影下列论述错误的是（）.

A.无需向血管内注射对比剂

B.仅向血管内注射少量对比剂

C.简单安全，属于无创性检查

D.常用技术有时间飞跃和相位对比

E.适用于各种血管病变的检查

Construction of the gigantic office building in this city was for years intermittent .

A．stopping and starting at intervals

B．something that will happen soon

C．being watched with keen interest

D．anything that comes and goes