--- Jack fell off the ladder yesterday, but he is all right now.
---What a lucky dog! He _______ himself badly.
A. could injure B. must have injured
C. should injure D. might have injured
---Tell us, Mark, what is the cause of the American Civil War?
---Well, is it _______the black slaves wanted freedom?
A. how B. why
C. because D. when
--- I can’t carry the luggage. It’s so heavy.
--- Why not have someone strong enough_______ you a hand then?
A. give B. to give
C. giving D. to have given
Although she brushed the old pot_______, she could not make it completely clean, which made her very upset.
A. roughly B. thoroughly
C. instantly D. occasionally
Mr. Smith is always on time for everything. How ____ it be that he was late for the important meeting?
A. should B. can
C. may D. must
---Your grandfather still seems very energetic, although he is already in his seventies now.
---Yes, he _______in the army for three years when he was young.
A. would serve B. served
C. had served D. has served
