50. Is there a gas station around _____ I can get some petrol?

A．which

B．what

C．where

D．That

如图甲、乙两个装置均可通过胶头滴管向锥形瓶中滴加某种液体，达到使气球鼓起的目的，锥形瓶和胶头滴管放入物质正确的一组是

      装置名称      锥形瓶内物质       胶头滴管中物质

A.       甲                 HCl气体               NaOH溶液 

          乙                 NaCl固体              H₂O

B.       甲                 CaCO₃                  稀盐酸 

          乙                 固体NaOH            H₂O

C.       甲                 NH₃                     H₂O 

          乙                 Cu                        稀盐酸

D.      甲                 CO₂                      NaOH溶液 

          乙                锌粒                      稀硫酸