1．Thank you for sending us ______ fresh vegetables of many kinds. You have done us ______ great service.
A. 不填；a B. the；a C. 不填；不填 D. the；不填
2. Please do me a favor— ______ my friend Mr. Smith to Youth Theatre at 7:30 tonight.
A. to invite B. inviting C. invite D. invited
3. --- The MP3 cost me about 2,000 Yuan.
--- Well, it was crazy of you to spend so much money ______ you could buy a cheaper one.
A. when B. unless C. if D. because
