开展国际经济合作的基本原则是()
《海关法》规定的纳税期限为海关填发税款缴纳证之日起()
An A4 sized panel ( 太阳能板 ) put onto the back of a jacket costs __________ US$15. It could __________ a cellphone during a summer walk.
—Shall we go outing this weekend?
—Oh, with all this work ______ ____,I don ’ t know if I ’ ll have time to go out.
在回归模型中，t统计值的大小表示()
