1( Essential)a nineteenth-century instrument, the calliope was usually played outdoors and was (a part) of fairs, (holiday) gatherings,and (other such) activities.

2 Citrus (fruits) (thrive) in (quite very) tropical (climates).

谢谢

A essentially

C 都去掉或者留very

是真题吧，置顶的大全里都有解释。