21. Does it make any difference ____exchange students speak British or American English?
A. whether B. which C. if D. that
22. you can’t imagine what great difficulty I have _____an item from the list.
A. omitting B. to omit C. omitted D. been omitted
23. The combination of parties to form a new government turned out to be _____failure, but as we know, success often comes from ______failure.
A. a; a B. / ; / C. a; / D. / ; a
