二、单项填空（共16小题; 每小题0.5分，满分8分）
从A、B、C、D四个选项中，选出可以填入空白处的最佳选项，并标在试卷的相应位置。
18. I often have conversations with John on phone while keeping in touch with
Tom by____letter.
A. /; the B. /; a C. the; / D. a; a
19.Whether to keep the three customary holidays(小长假) is a subject _________ Chinese netizens have argued a lot recently.
A. with which B. of which C. into which D. about which
20. Barbara is easy to recognize as she is the only one of the women who_________ evening dress.
A. wear B. wears C. is wearing D. are wearing
21.Zhao Benshan is really an excellent actor, whose subtle acting always makes everything _________.
A. delight B. delighted C. entertaining D. entertain
22 Farmers provide us with food. However, they are _________by some citizens.
