妊娠高血压综合征出现高血压与哪些因素有关:
A.血管紧张素增加
B.醛固酮分泌增加
C.子宫胎盘源性前列腺素合成下降
D.血液浓缩
E.以上都是
参考答案:A,B,C
Some people who don’t like to talk much are not necessarily shy; they _____ just be quiet people.
A.must
B.may
C.should
D.would
为order_list表创建一个主索引,索引名和索引表达式均是“订单号”。