---Look at these tracks. It _____ be a wolf.”  ---Don’t be so sure. I think it _____ be a fox.
#87712
A
must; could
B
may; might
C
need; must
D
could; need
推荐题目
Eliza remembers everything exactly as if it _________ yesterday. 
#90453
A
was happening
B
happens
C
has happened
D
happened
—Shall we go skating or stay at home?—Which       do yourself?
#89658
A
do you rather
B
would you rather
C
will you rather
D
should you rather
—You didn’t invite Mary to the ball?—____ her, too? 
#89489
A
Must I invite
B
Should I have invited
C
Must I have invited
D
Should I invite