动脉导管未闭脉压差增大的主要原因是
A.心脏存在着异常的通道
B.主动脉的血分流至肺动脉
C.肺循环血流量的明显增多
D.体循环血流量的明显减少
E.收缩压的明显升高
参考答案:D
—What do you think about ________ blue dress in the shop window?
—Oh, it's fantastic! It will make ________ perfect birthday present.
A.a; a
B.the; a
C.a; the
D.the; the
内浇口的设计要点。