题干

物质的变化会受到诸多因素的影响,请根据下列变化的现象或结果的差异以及题给示例,说出相应的影响因素。

现象或结果的差异

影响因素

示例:生铁容易锈蚀,而钢则不易锈蚀。

物质的组成

①澄清石灰水中通入适量的二氧化碳后会变浑浊,但持续通入二氧化碳后浑浊又会变澄清。

____


②一氧化碳能将红棕色的氧化铁还原成黑色铁粉,二氧化碳则不能。

____


③二氧化碳通入水中后能和水反应生成碳酸,在绿色植物的叶绿素内二氧化碳和水却能转化为葡萄糖和氧气。

____


④石灰石粉末和稀盐酸的反应速率大于块状石灰石和稀盐酸的反应速率。

____


上一题 下一题 0.0难度 选择题 更新时间:2014-05-09 12:48:37

答案(点此获取答案解析)

反应物的量,分子的构成,反应条件,反应物之间的接触面积

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Habits to Be a Highly Effective Student

    Some students are able to get straight A's and at the same time serve as the president of three clubs. However, some students struggle to keep their GPA (Grade-Point Average) above a 3.0____Although it's true that everyone's IQ is different, good study habits are very important. Here5re several habits you should adopt to get good grades.

    ____ If you haven't had a planner (规划薄), get one. Many people use their computers and smartphones to make a schedule. The problem with that approach is that they are major distractions (分心的事物). Instead, get an old-fashioned paper and pen planner.

    Create a weekly schedule____Include time that will be spent eating, sleeping and doing anything not related to school work. That way you know exactly how much you can accomplish each day.

    Take frequent, short breaks. Taking a break from studying for 15 minutes every hour will help keep you refreshed____ If you don't take a break, you may find yourself daydreaming or even falling asleep. Take some time for some water, a snack or a quick chat with a friend.

    Take care of yourself. During final exam week, it is common for students to fall behind on sleep and meals. Make sure you get a good night's sleep and have regular meals. Studying while hungry or sleepy is ineffective and will slow you down in the long run. Also try to make time for friends and family____

A. Keep things organized.

B. Keep away from your computers.

C. Of course, not everyone needs breaks.

D. Our brains are not meant to work for hours nonstop.

E. Having a good support system will help with all the stress.

F. And they seem to spend all of their time in studying.

G. Then under each day, make a list of things to do each hour.