题目

在植物体细胞杂交技术中，重要一环是将植物细胞的细胞壁除去，通常采用的方法是酶解破壁法。你认为普通的植物细胞去除细胞壁所用的酶应选择（） A . 纤维素酶和淀粉酶 B . 麦芽糖酶和纤维素酶 C . 纤维素酶和果胶酶 D . 麦芽糖酶和果胶 答案：COnce upon a time, there was a group of forest deer. In this group was a wise and respected   36 , smart in the ways of deer. He taught the tricks of   37  to the fawn-the young deer.One day, his younger sister   38  her son to him, to be taught   39  is so important for deer. The teacher said to the fawn, “Very well, you can come at this time tomorrow for your first   40 .”At first, the young deer came to the lessons   41  he was supposed to. But soon, he became more interested in   42  with the other young bucks（雄鹿）. He didn’t realize how   43  it could be for a deer who learned   44  but deer games. So he started  45 . Soon he was escaping school all the time.  46 , one day the fawn who played hooky   47  a snare（陷阱）and was trapped. Since he was   48 , his mother got worried. She went to her brother the teacher, and  49  him if her son had learned something. The teacher   50 ,”My dear sister, your son was disobedient and   51 . Out of respect for you, I   52  to teach him. But he did not want to learn the   53  of deer. He played hooky! How could I possibly teach him?”Later they heard the sad news. The   54  fawn had been trapped and killed by a hunter. He skinned him and took the meat home to his family.The moral is: Nothing can be learned from a teacher by one who   55  the class.小题1:A．studentB．motherC．teacherD．magician小题2:A．performB．survivalC．huntingD．hiding小题3:A．broughtB．caughtC．arrangedD．referred小题4:A．thatB．whichC．howD．what小题5:A．arrivalB．punishmentC．prizeD．lesson小题6:A．asB．becauseC．whetherD．where小题7:A．learningB．playingC．talkingD．fighting小题8:A．interestingB．boringC．dangerousD．useful小题9:A．nothingB．somethingC．allD．none小题10:A．working hardB．cutting classesC．playing gamesD．teaching others小题11:A．LuckilyB．UnexpectedlyC．DefinitelyD．Unfortunately小题12:A．found outB．set upC．stepped inD．got over小题13:A．dyingB．missingC．unhappyD．improving小题14:A．toldB．scoldedC．askedD．suspected小题15:A．repliedB．analyzedC．advisedD．questioned小题16:A．unbelievableB．unreachableC．inflexibleD．unimportant小题17:A．made up my mindB．tried my bestC．gave upD．would like小题18:A．storiesB．structuresC．gamesD．tricks小题19:A．proudB．sickC．stubbornD．shy小题20:A．missesB．lovesC．formsD．attends