题目

在做“叶绿体色素的提取和分离”实验过程中，研磨绿叶时，加入少许CaCO3的目的是： A.使研磨更加充分                             B.使色素分离更彻底 C.使色素充分溶解在丙酮（或无水乙醇）中       D.防止叶绿素被破坏 答案：DI always had a dream. In it, I was a little girl again, rushing about, trying to get _______for school. Deep inside I knew _______it came from. It was some unfinished_______in my life.As a kid I loved school. Most of all I_______to receive my diploma. That seemed more_______even than getting married. But at 15, I had to _______because my parents couldn’t afford my _______. Pretty soon, I married and had three children. I thought, “There goes my diploma.” _______, I wanted my children to be educated. But Linda, the youngest, had a serious heart disease, which made it impossible for her to_________in a normal classroom.One day, I saw an ad for evening courses. “That’s the __________. Linda always feels better in the evening, so I’ll just __________ her up for night school.”Linda was busy filling forms when the school__________ said: “Mrs. Schantz, why don’t you come back to school?”I laughed: “There’s no __________! I’m 55!”But he __________me and I attended class with Linda. Surprisingly, both Linda and I felt great there and my__________ steadily improved.It was exciting, going to school again, but it was no __________. Sitting in a class full of kids was__________, even if most of them were respectful. Whenever I was down, Linda encouraged me. “Mom, you can’t __________now!” Together we made it__________.Finally, I got my diploma with Linda and realized my __________of years.1.A. started B. concerned C. finished D. prepared2.A. when B. where C. how D. why3.A. homework B. diploma C. accident D. business4.A. required B. managed C. longed D. struggled5.A. annoying B. incredible C. appealing D. ridiculous6.A. drop out B. give in C. break up D. turn away7.A. living B. teaching C. working D. schooling8.A. As usual B. Until then C. Even so D. In fact9.A. recover B. function C. benefit D. arrive10.A. problem B. answer C. deal D. result11.A. sign B. put C. call D. pick12.A. secretary B. colleague C. employer D. referee13.A. rush B. time C. way D. class14.A. urged B. demanded C. persuaded D. informed15.A. grades B. attitude C. health D. moods16.A. fun B. game C. good D. wonder17.A. available B. awkward C. awesome D. awful18.A. miss B. reject C. resign D. quit19.A. up B. out C. off D. through20.A. dream B. ambition C. plan D. thought