The seaside beach turned out to be very beautiful,     was more than the tourists had expected. [ ] 

A. what

B. that

C. which

D. where

生态系统是由（）。

A.生物群落构成

B.生物群落及其非生物环境组成

C.人类聚居而成

D.人类与其他生物组成

E.人类与非生物系统构成