khá khó! 1. _______ will the course start? - On July 15 a. when b. where c. what time d. how long 2. how long did the song last? - a. 20 centimeters b. since 2004 c. in september d. for 4 minutes 3. why did he stopped smoking? - ________ a. to cough too much b. when he knew that her was going to die c. because he had been coughing too much d. since he has coughed too much 4. she has just applied for a(n)_______ organization a. non-profit b. no-profit c. unprofitable d. profitless mình cần lời giải thích cho đáp án bạn chọn.