某有机化合物的结构简式如下：此有机物属于[ ] ①烯烃②多官能团有机化合物③芳香

下列装置中，不能检验气密性的是______．

汉译英：“保函；信用证；许可证”，正确的翻译为：( )。

A. letter of credit; letter of guarantee; license
B. letter of guarantee; letter of credit; license
C. letter of guarantee; license; letter of credit
D. license; letter of credit; letter of guarantee

If an airplane circles a vessel 3 times，crosses the vessel’s course close ahead while rocking the wings，and heads off in a certain direction，what does this indicate?（）

A.The plane is in distress and will have to ditch

B.The plane is going to drop a package and wishes the vessel to recover it

C.Someone is in distress in that direction and the vessel should follow and assist

D.There is danger ahead and the best course is indicated by the direction of the aircraft

下列关于“10200身份证号码升位”交易的联网核查要求，表述正确的是（）。

A、出示核查留存不允许代理

B、出示核查留存允许代理

C、出示核查不留存允许代理

D、出示不核查留存不允许代理

实施劳动合同报告和公积金业务联动后，园区的用人单位在实施劳动合同书面报告时，应同时向园区劳动合同管理经办窗口报送（）信息。

A、用人单位录用外来人员

B、公积金参保

C、员工参加培训的

D、用人单位工资水平