23 I took my jacket with me ( ) it should get cold in the evening.
　　　① because　② although　③ in case　④ unless

24 I went to bed earlier than usual ( ) I had an early flight the next morning.
　　　① since　② or　③ while　④ though

25 Takashi can borrow my book ( ) he promises to retun it by Friday.
　　　① if　② even　③ unless　④ except

26 I will not be able to prepare the meal on time ( ) you help me.
　　　① except　② unless　③ if not　④ whether

27 I'm sure William will win, ( ) he doesn't make any serious errors.
　　　① provided　② provide　③ provides　④ proving

28 ( ) you have mastered the basics, you will probably want to know more about your computer.
　　　① During　② Once　③ Therefore　④ So

29 ( ) Tokyo has a relatively small land area, it has a huge population.
　　　① Although　② But　③ Despite　④ However

30 You can sometimes feel lonely even ( ) you are surrounded by friends.
　　　① as　② if　③ so　④ since

31 ( ) he set three alarms in his room, he still failed to wake up on time.
　　　① Because　② But　③ No matter how　④ Even though

32 ( ) you like it or not, you need to be here by six tomorrow morning.
　　　① Even if　② Either　③ Because　④ Whether

33 ( ) we climbed higher, the air became thinner.
　　　① During　② Until　③ As　④ So