英语选择题~请给出答案说解析,谢谢

英语选择题~请给出答案说解析,谢谢18. Now there are many opportunities ______ you can show your talent in our school. A. in which B. that C. which D. of which 20. Chris, what’s wrong with you? That’s the sixth cup of coffee you ______ today. —Nothing serious, mum I just feel tired and sleepy. A. have B. had C. are having D. have had 24. While Microsoft just started its exploration into tablet computers, Apple has decided to go a different way ______ its iPad smaller and easy to carry. A. to make B. making C. made D. having made