问题 选择题

下面有关碳酸钠和碳酸氢钠说法不正确的是

A.碳酸氢钠不稳定,受热易分解

B.碳酸氢钠可以用作治疗胃酸过多的药物

C.碳酸钠溶液显碱性,所以碳酸钠是碱

D.碳酸钠既是钠盐、又是碳酸盐、还是可溶性盐

答案

答案:C

题目分析:A碳酸氢钠不稳定,受热分解产生碳酸钠、二氧化碳和水。正确。B碳酸氢钠y与盐酸反应产生氯化钠、二氧化碳和水。故可以治疗胃酸。正确。C、碳酸钠溶液显碱性,但是碳酸钠在物质的分类上是属于盐。错误。D、碳酸钠阳离子是钠离子,阴离子是碳酸根离子,所以它既是钠盐、又是碳酸盐;所有的钠盐都容易溶解在水中,因此还是可溶性盐。正确。

阅读理解

Active vacations are often the most relaxing of all. But Wait! It's all in defining what an active vacation is. We don't expect you to take up jogging, backpacking, or hang gliding. we ask the sedentary(爱坐的)vacationers to spend two to four hours a day doing things, such as walking the city streets, exploring a nature preserve, or taking a leisurely rowboat ride.

These kinds of activities aren't just good for your physical health. They improve your mental health, even your spiritual health. And they make vacations memorable and worthwhile. Here are some fresh ideas for active and healthy vacation.

Make the morning your activity time. At that time it is most likely that the weather will be friendlier, your energy level higher, and your schedule emptier than later in the day.

Have a walk at dawn or dusk. Such activity is called rejuvenation(恢复活力). Try to make this a daily routine of life away from home, and you will guarantee yourself both physical and spiritual youth.

Get into the water as much as you can. Don't allow yourself to spend your entire time sitting in front of the water. Whether it is the ocean, a swimming pool, or a tree-lined lake, make sure you get into the water for swimming or games or even walking. Merely standing in waist-high water is a good workout, thanks to the action of the water. And you'll feel so much more alive!

Choose a cruise for your trip. It's amazing how active you can be being stuck on a boat in the middle of the Atlantic. Most cruise ships offer numerous options for seaworthy exercise. During your sea and land trips you can burn calories as you swim, hike, dive, and horseback ride.

Get out of the car every two hours. Many of us spend a large part of our vacations on the road, either getting to and from our destinations, or using the car for sightseeing. But no matter how beautiful the scenery is, great and memorable vacations don't happen in a car seat. Don't wait for tiredness or nature's call to get you to pull over. Frequently get out and stretch, walk, picnic, shop, visit, and have fun. It's important for your health and energy, and it makes traveling a lot more active and interesting.

小题1:The first paragraph mainly tells us ____________.

A.that active vacations are very relaxing

B.the activities we should join in

C.how many hours we should exercise every day

D.what an active vacations is小题2:How many tips does the writer give in the passage?

A.Three

B.Four

C.Five

D.Six小题3:Which of the following is WRONG according to the passage?

A.Usually the weather in the morning is better.

B.You can have a memorable vacation in a car.

C.Swimming can make you feel much more alive.

D.Don’t drive your car very often to go sightseeing.小题4:Which of the following is probably the best title for this passage?

A.Driving Tips

B.How to Relax Without cars

C.Give up Your Car and Walk

D.Make your Vacation Healthy

单项选择题