现已制成缓释钾制剂市售品（如slow-K），这是通过以下哪种方法实现的 A．利用一种

幽门螺杆菌感染的途径是：口－口、粪－口途径及医源性传播，如胃镜检查／活检等。

看图填出“战国七雄”的名称：

A_______________B______________C______________D______________

E______________F______________G______________

Organic food is produced from crops _____ chemicals, pests and so on. In one word, it is free from

pollution of any kind.   [ ]

A. that is free from  

B. free of    

C. free with  

D. which are free of

如图所示是一定质量的气体从状态A经过状态B 到状态C的p-T图象，由图象可知

A．V_A=V_B

B．V_B=V_C

C．V_B＜V_C

D．V_A>V_C