题目

常见的酿酒酵母只能利用葡萄糖而不能利用木糖来进行酒精发酵，而自然界中某些酵母菌能利用酶A分解木糖产生酒精。请分析回答下列问题：（1）制作果酒与果醋的菌种在结构上的主要区别是_________。（2）将自然界收集的酵母菌菌株转接到仅以___________为碳源的培养基中，________（填“有氧”或“无氧”）条件下培养一周后，有些酵母菌死亡，说明这些酵母菌不能利用木糖发酵。（3）将搜集到的酵母菌放入培养液中扩大培养后，用稀释涂布平板法计Wang Lin is a middle school student. He likes English very ___1__. He _____2__ gets up at six in the morning. It’s so early. Then he ____3____ morning exercises. He reads English ___4___ half past six to ten past seven. He can recite(背诵) all the drills(句型) and the texts. In class, he _5 the teacher carefully. And he always answers the __6__ questions. After class he likes __7__ with his classmates in English. Sometimes he helps some of his classmates __8_ their English.    In the evening, he often __9_ newspapers. They give him more help. He often says, “I must _10__ hard at English.” 1 A. much                    B. good                C. well                 D. friendly 2 A. usual                    B. often           C. only              D. also 3 A. do                     B. is doing       C. does               D. doing 4 A. from                         B. at                    C. on                    D. to 5 A. sees                         B. listens to          C. reads               D. hears 6A. teachers             B. teacher’s         C. students’          D. others’ 7 A. speak                   B. talk                  C. talking              D. saying 8 A. in                  B. for                C. with                D. at 9 A. watches               B. reads               C. looks               D. looks at 10 A. study               B. to study           C. studying           D. studies