Hỗn hợp khí gồm 1 hiđrocacbon no, mạch hở X và 1 hiđrocacbon không no Y vào bình nước brom chứa 40 gam brom. Sau khi brom phản ứng hết thì khối lượng bình tăng lên 10,5 gam và thu được dung dịch B, đồng thời khí bay ra khỏi bình có khối lượng 3,7 gam. Đốt cháy hoàn toàn lượng khí bay ra khỏi bình thu được 11 gam CO₂. Có bao nhiêu chất X thỏa mãn điều kiện trên?

A. 2 chất

B. 1 chất

C. 3 chất

D. 4 chất

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that bestfits each of the numbered blanks.

      The latest addiction to trap thousands of people is Internet, which has been (35) x for broken relationships, job losses, íinacial ruin and even one suicide. Psychologists now recognize Internet Addiction Syndrome (IAS) as a new illness that could (36) x serious problems and ruin many lives. Special help groups have been set up to (37) x sufferers help and support.

      IAS is similar to (38) x problems like gambling, smoking and drinking : addicts have dreams

about Internet; they need to use it first thing in the morning; they (39) x to their partners about how much time they spend online; they (40) x they could cut down, but are unable to do so . A recent study found that many users spend up to 40 hours a week on the Internet; (41) x they felt guilty, they became depressed if they were (42) x to stop using it.

Almost anyone can be at risk. Some of the addicts are teenagers who are already hooked on Computer games and who (43) x it very difficult to resist the games on the Internet. Surprisingly, however, psychologists (44) x that most victims are middle-aged housewives who have never used a computer

before.

Điền vào số 41

A. unless

B.without

C.although

D.despite