水能是（）的清洁能源。
A.资源最丰富
B.技术最成熟
C.已开发规模最大
D.经济性最高
E.分布最广泛
参考答案：B, C, D
Choose the words and fill in the blanks. 选词填空。
A: May I (help, helping) you?
B: Yes! I want to buy a (dress, dresses). Where are the (dress, dresses)?
A: I'll (show, shows) you. This (way, dress), please. Here they (is, are)!
B: Thanks!
食管上、下段均闭锁，无食管气管瘘( )
A．Ⅰ型食管闭锁B．Ⅱ型食管闭锁C．Ⅲ型食管闭锁D．Ⅳ型食管闭锁E．Ⅴ型食管闭锁
