三道高中英语单选.1、People around the world_________Christmas Tree ev
三道高中英语单选.
1、People around the world_________Christmas Tree ever since 1510.
A、decorated
B、have decorated
C、have been decorated
D、have been decorating
2、The small country_______since the 1880s.
A、has come into existence
B、has been in existence
C、has been existed
D、has begun to exist
3、_____ at the back of the room was a shy girl with two big eyes.
A、Sit
B、Sat
C、Seated
D、Seating
C和D怎么选?
第三题的B为什么不选?