若|3a+b+5|+(a﹣b﹣1)2=0,则2a2﹣3ab的值是( ).
﹣4
— What’s wrong with you, sir?
— My flight ______ ten minutes ago. What should I do?
A.took up
B.took off
C.got on
D.got off
边缘性前置胎盘 * * 流血时间多出现在妊娠()。
A.14~18周
B.18~24周
C.24~28周
D.28~36周
E.37~40周