迄今，诊断动脉导管未闭的"金标准"是（）。
A.X线平片
B.CT
C.MRI
D.超声心动图
E.心血管造影
参考答案：E
The careless driver is ________ for the traffic accident that _____ yesterday.[ ]
A. to blame; happened
B. to blame; was happened
C. to be blamed; was happened
D. to be blamed; happened
恩格尔系数减少，意味着（）
A.消费水平提高
B.食品支出数量减少
C.生活质量下降
D.消费结构不合理
that _____ yesterday.[ ]