1.单选题- (共5题)
A.与葡萄糖互为同分异构体 |
B.可以与银氨溶液作用形成银镜 |
C.可以与FeCl3溶液作用显色 |
D.可以使紫色石蕊试液变红 |
A.乙烯和聚乙烯均能使溴水褪色 |
B.甲烷、苯和油脂均不能使酸性KMnO4溶液褪色 |
C.乙酸和乙酸乙酯均能发生取代反应 |
D.葡萄糖与果糖、淀粉与纤维素分子式相同,均互为同分异构体 |
A.生物柴油是不同酯组成的混合物,可用“地沟油”制得 |
B.合成纤维、人造纤维及碳纤维都属于有机高分子材料 |
C.纤维素在人体内可水解为葡萄糖,故可做人类的营养物质 |
D.聚乙烯塑料制品可用于食品的包装,该塑料的老化是由于发生了加成反应 |
A.淀粉、油脂和蛋白质都是高分子化合物,且它们均为混合物 |
B.煤、石油和天然气都是化石燃料,且它们均不能再生 |
C.果糖、蔗糖和麦芽糖都能发生水解反应,且产物均为葡萄糖 |
D.乙酸和葡萄糖都能与新制的Cu(OH)2反应,且反应类型均为氧化反应 |
A.淀粉和纤维素的分子式均为(C6H10O5)n,它们互为同分异构体 |
B.乙醇和乙酸都是常用调味品的主要成分 |
C.聚氯乙烯能使溴的四氯化碳溶液褪色 |
D.人体不能消化纤维素,所以纤维素在人体中作用不大,人可以不吃富含纤维素的食物 |
2.选择题- (共6题)
Each summer,you hear news that some sports players are sent to hospitals because it is too hot. Our bodies can't be outside in the sun for a long time. So in hot summers,be careful about playing sports outside.
Firstly,to play sports safely in hot weather,you must drink water. Sports drinks are great for athletes,but they have so much sugar that they'll dehydrate(使脱水)you more. However,drinking a few bottles of sports drinks will be good for you.
Secondly,be sure to take enough breaks to let your body rest. If your coach doesn't let you take enough breaks in the heat,don't wait until you feel uncomfortable. Just be honest with your coach when you need breaks.
Thirdly,when you have a break,don't sit in the sun. With the sun beating down on you,you'll only heat up and sweat(冒汗)more. Take a seat under a tree,or even better,go indoors for a little while. Cooling yourself down can help you stay active longer.
Fourthly,remember that the earlier in the day you start your exercise,the cooler it will be. If you can start practice before the sun comes up,you have a few good hours to practise in the cool hours of the morning. Also,the earlier you practise,the earlier you can finish the exercise. If you need more practice time,come back to the field later in the evening,when the sun is setting.
Last but not least,you should watch what you eat. Eat food which is high in water,starch(淀粉)and carbonhydrate(糖类),but be sure to get a good balance in your diet.
As long as you pay attention to the above,playing sports safely in the heat isn't a difficult thing.
Each summer,you hear news that some sports players are sent to hospitals because it is too hot. Our bodies can't be outside in the sun for a long time. So in hot summers,be careful about playing sports outside.
Firstly,to play sports safely in hot weather,you must drink water. Sports drinks are great for athletes,but they have so much sugar that they'll dehydrate(使脱水)you more. However,drinking a few bottles of sports drinks will be good for you.
Secondly,be sure to take enough breaks to let your body rest. If your coach doesn't let you take enough breaks in the heat,don't wait until you feel uncomfortable. Just be honest with your coach when you need breaks.
Thirdly,when you have a break,don't sit in the sun. With the sun beating down on you,you'll only heat up and sweat(冒汗)more. Take a seat under a tree,or even better,go indoors for a little while. Cooling yourself down can help you stay active longer.
Fourthly,remember that the earlier in the day you start your exercise,the cooler it will be. If you can start practice before the sun comes up,you have a few good hours to practise in the cool hours of the morning. Also,the earlier you practise,the earlier you can finish the exercise. If you need more practice time,come back to the field later in the evening,when the sun is setting.
Last but not least,you should watch what you eat. Eat food which is high in water,starch(淀粉)and carbonhydrate(糖类),but be sure to get a good balance in your diet.
As long as you pay attention to the above,playing sports safely in the heat isn't a difficult thing.
-
【1】题量占比
单选题:(5道)
选择题:(6道)
-
【2】:难度分析
1星难题:0
2星难题:0
3星难题:0
4星难题:0
5星难题:0
6星难题:0
7星难题:0
8星难题:2
9星难题:3