I had wanted to visit the gallery before I            Florence, but it' s closed on Sundays.

A．left

B．has left

C．leave

D．would leave

既是肾上腺素能q受体激动剂又是肾上腺素能p受体激动剂的是（）

A．盐酸去甲肾上腺素

B．盐酸多巴胺

C．盐酸肾上腺素

D．盐酸克仑特罗

E．盐酸异丙肾上腺素