问题 完形填空
根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
Being a good student doesn’t mean you have to drop all social activities and dive in your books. It is still possible to have a healthy social life while getting good grades. __1___ Here’s how you can achieve it:
1.  Decide for yourself at the start of the term that you won’t let your schoolwork sweep you away. ___2__
2.  Write down your weekly schedule on a piece of paper. Chances are,you’ll have small gaps between classes during the week and more free time at the weekend. Make sure that every time you find yourself in one of those between-class gaps you use the time efficiently.___3__
3.  Set aside at least one large amount of time each week as free time. Keep in mind the law of diminishing returns (收益递减). Past a certain point, more hours of studying will be of little benefit. __4__ Protect both your free time and your school time carefully. If one starts to infringe (入侵)on the other, that is just the beginning of a long, slippery downhill slope.
4.  __5__ This way, you can co-ordinate(协调) your free time with theirs.
5.  Whenever possible, find social activities that take you off campus and away from your schoolwork.
A.  Balance is the key.
B.  Encourage your friends to follow your similar plan.
C.  It is very important to be determined about this.
D.  Try not to affect other’s time and just focus on your own.
E.  You are better off spending this time with friends.
F.  You can spend more time on social life than on study.
G.  Read a few pages of your school book or do some quick chores, for example.
答案

小题1:A

小题2:C

小题3:G

小题4:E

小题5:B

小题1:由上文可知好学生不一定要放弃社会活动埋头学习,重要的是把二者结合起来。

小题2:由上文可知在学期开始时就要下决心。

小题3:上文提及我们要充分利用好空闲时间,那么G正是在空闲时间可以做的事情、

小题4:本段讨论的是时间分配的问题,要留时间陪朋友,F选项中的more表达不准确。

小题5:根据下文的你可以协调你和他的空闲时间,推断出B符合要求。

实验题

萌发的禾谷类种子中淀粉酶的含量显著增高,主要有α-淀粉酶和β-淀粉酶。α-淀粉酶不耐酸、较耐热,在pH为3.6、0℃下可迅速失活,而β-淀粉酶耐酸、不耐热,在70℃条件下15min后失活。根据它们的这种特性,可分别测定一种酶的催化效率。某实验小组进行了“提取小麦种子中α-淀粉酶并测定α-淀粉酶催化淀粉水解的最适温度”等相关实验。

实验材料:萌发3天的小麦种子(芽长约1cm)。主要试剂及仪器:1mg/mL的标准麦芽糖溶液、5%的可溶性淀粉溶液、碘液、蒸馏水、石英砂、恒温水浴锅等。

实验步骤:步骤一:制备酶溶液。

步骤二:略。

步骤三:取6支干净的、体积相同并具刻度的试管依次编号,按下表要求加入试剂,再观察各试管内的颜色变化。(注:+表示碘液变蓝色,-表示碘液不变色)

请回答下列问题:

(1)资料表明:小麦种子发芽时,胚产生赤霉素,赤霉素扩散到糊粉层,诱导淀粉酶的合成。赤霉素诱导淀粉酶合成的主要机理是_________________________________。选用萌发的小麦种子提取酶液的主要理由是________________________。

(2)步骤二的具体操作是________________________________________。

(3)加入碘液,振荡后观察颜色变化,发现试管4中碘液不变色,能否据此推断α-淀粉酶的最适合温度一定是60℃?_________________。理由是_________________________________。该实验中不能选用斐林试剂检测实验结果的主要原因是____________________________。

(4)若要进一步研究小麦种子中β-淀粉酶的最适温度,则需获得β-淀粉酶保持活性而α-淀粉酶失活的酶溶液。请简要写出制备该种酶溶液的方法:_________________________。

单项选择题 B型题