全心衰竭（）
A.肺性发绀
B.混合性发绀
C.淤血性发绀
D.缺血性发绀
E.心性混血性发绀
参考答案：B
There _____ great changes in our school since 1979. [ ]
A. have been
B. were
C. has been
D. are
贷记卡持卡人如需打印对账单，可在全国任意营业机构办理。
