—— Where did Mary’s parents buy the beautiful vase?

—— It was in the same village _______ they spent their holidays last year.

A．that

B．when

C．as

D．where

上皮角化不全，夜盲症，繁殖机能障碍是（）

A．维生素A缺乏 

B．维生素B缺乏 

C．维生素D缺乏 

D．维生索K缺乏 

E．维生素E缺乏