临床上最常见的联合瓣膜病是A．三尖瓣狭窄合并肺动脉狭窄 B．二尖瓣狭窄合并主动脉瓣狭

纳税人破产，依法终止纳税义务的，( )不是注销税务登记的前提。

A．缴销税务登记证

B．缴销营业执照

C．结清税款滞纳金

D．缴销发票

句型转换。

1. Jack likes dolphins because they're smart and interesting. (划线提问)

    _____ _____ Jack like dolphins?

2. Our school is near here in front of a big park. (划线提问)

    _____ _____ your school?

3. My pen pal is from Canada.(同意转换)

    My pen pal _____ _____ Canada.

4. They speak English and French. (划线提问)

    _____ _____ do they speak?

5. Jean likes dogs and cats best. (同意转换)

    Jean's _____ _____ are dogs and cats.

具有升华性的生物碱是( )

A．烟碱
B．麻黄碱
C．川芎嗪
D．小檗碱
E．甜菜碱

柏克德公司长期以来始终树立（）的指导思想。

A.一切都是为了企业利益

B.一切事故都是可以避免的

C.一切都是为了企业的效益