问题 单项选择题

下列关于栈的叙述中正确的是______。

A.在栈中只能插入数据

B.在栈中只能删除数据

C.栈是先进先出的线性表

D.栈是先进后出的线性表

答案

参考答案:D

解析: 栈是一种特殊的线性表,这种线性表只能在固定的一端进行插入和删除操作,允许插入和删除的一端称为栈顶.另一端称为栈底。一个新元素只能从栈顶一端进入,删除时,只能删除栈顶的元素,即刚刚被插入的元素。所以栈也被称为“先进后出”表或“后进先出”表。

阅读理解

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。

If you garden for pleasure, you may not be aware of how beneficial this hobby is for your health. While you are preparing your garden to grow fresh plants, you are actually doing an amount of exercise as well. Basic yard care tasks such as cleaning the grass or moving fallen leaves away are also good ways to get physical exercise.  小题1:. Just think of the mental relaxation you experience when working in the garden.

Various health experts and university studies show that gardening and yard work are more than just enjoyable hobbies.  小题2: . This is truly a great thing as you can use your whole body while you are working. Gardening also involves a number of different kinds of exercise, including stretching and weight lighting.

Activities in the yard and garden are also a form of exercise that is appropriate for a variety of people and age groups. Depending on the activity, gardening and yard work are not quite as hard on your body as jogging or running.  小题3: Like other forms of exercise, gardening can help lower blood pressure and cholesterol (胆固醇) levels and keep away heart disease. Moreover, it helps burn a lot of calories.

 小题4:. But you can increase the amount of time you spend gardening to improve your health even more. If you are not an active gardener, think about starting a small garden. This way, you can combine the joys of growing your own food with light exercise.

When gardening, like other forms of exercise, you need to follow a few basic tips to maximize your experience. First, you should warm up a bit. Do some basic stretches so that your muscles are ready.  小题5: . This is especially important if you are not already an active gardener.

A.They are also unique forms of exercise that allow you to do something creative and fun.

B.Then if you plan to lift heavy objects, always lift them with your knees, not your back.

C.Additionally, gardening and yard care are beneficial for your mental health, too.

D.In the winter, you may wonder what kinds of activities you can do in the garden.E.There are a lot of activities that you can do in your yard and garden.

F.This means that even if you are older, you can still enjoy the exercise.

G.If you already garden, good for you!

单项选择题