问题
选择题
Once ___, it can never be forgotten.
A.see
B.to be seen
C.seen
D.saw
答案
答案:C
seen是过去分词,它用作时间状语时,常与once, when, whenever, while,until一起用.
Once ___, it can never be forgotten.
A.see
B.to be seen
C.seen
D.saw
答案:C
seen是过去分词,它用作时间状语时,常与once, when, whenever, while,until一起用.