II．单项选择(共15小题；每小题1分，满分15分)
21. Susan, ______ university student from Europe , teaches me _______ art in her spare time.
A. a, / B. a, the C. an, the D. an, /
22. His eyes stare at _____ is left of the brother’s dinner on the table.
A. which B. what C. that D. where
23. AIDS control and prevention is a _________ to China as well as the whole world.
A. surprise B. challenge C. threat D. reaction
24. The doctor advised Lisa strongly that she ______ a holiday but _______ didn’t help.
A. should take, which B. could take, which
C. might take, what D. take, it
25. It was in the lab ______was in the charge of Professor Smith ______they carried out the experiment.
A. which；where B. where；that C. that；where D. which；that
26. I would never speak to someone like that ________ they said something unpleasant to me.
