国际社会面临的安全威胁日趋综合化、多样化和复杂化，天下仍不太平。
参考答案：错
—Do you have Jay's CDs?
—sorry, they are _____. But we'll get some more next week because they _____.[ ]
A. sold well;are on sale
B. sold out;sell well
C. selling well;sell well
D. for sale;sell well
半桥粒的组成成分有()
A．BPAG
B．板层素
C．整合素
D．亲和素
