简述如何确诊艾滋病。

In relation to the basic legal system of China:

(b) state any one of the rules regarding the validity of a contract provided for in the judicial interpretations on the Contract Law by the Supreme People’s Court. (4 marks)

办税服务厅的主要职责是什么？

根据题图1-17所示的滑台向后控制梯形图，下列指令正确的是()

A、ANI100

B、AND100

C、ORI100

D、OR100

粉尘有哪些危害？

A．125.255.255.255

B．111.111.111.111

C．222.222.222.222

D．255.255.255.255