I am so tired,for I ________ English for 2 hours.
#99761
A
is studying 
B
have been studying
C
was studying 
D
had been studying
推荐题目
 All visitors to this village_________ with kindness.
#100165
A
treat
B
are treated
C
are treating
D
had been treated
You____________ television. Why not do something more active?
#104341
A
always watch
B
are always watching
C
have always watched
D
have always been watching