21. ---Could you do me a favor?
---It depends on _____ it is.
A. what B. which C. that D. where
22. The chief engineer was _______ directing the building of the bridge.
A. in the charge of B. in charge of C. in charge for D. in charge
23. I attended a meeting yesterday. The problems _______ at the meeting were closely connected with our daily life.
A. being discussed B. to be discussed C. discussed D. discussing
24. Only when the jellies went mouldy, _________ that they should have been put in the fridge to stay fresh.
A. I realized B. did I realize C. I had realized D. had I realized
25. The Internet makes the world much smaller and I _____ myself ____ a global citizen.
A. think…as… B. see…as… C. look…as… D. find…as…
