从A.B.C.D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
21. Don’t touch _______ live wire, or you will get _______ shock.
A. the; the B. the; a C. 不填; a D. 不填；不填
22. It was not what he said but the way he said it ________ hurt his son deeply.
A. when B. where C. that D. as
23. Henry could have declined the offer, ________ he had no interest in the program.
A. though B. when C. providing D. for
