首页
普通专升本
成人高考
学位英语
在线刷题
最近学习
最近学习课程
最强大脑 · 3天挑战极限记...
副标题副标题副标题副
最强大脑 · 3天挑战极限记...
副标题副标题副标题副
您现在位置：
模拟考场
>
湖北成人高考
>
专升本
>
生态学基础
>
浏览试题
[单选题]
下列条件中，能提高雏鸡的孵化率，降低“死胎”率的是 ( )
A
昼夜变温
B
恒温条件
C
高温条件
D
低温条件
收藏
查看答案
参考答案
试题答案：
A
答案解释：
相关题目
种群的年龄结构是指种群内个体的__________。
影响初级生产量的因素有水、CO2、日光、__________和温度、O2。
下列有关物质循环叙述正确的是（ ）
简述生态型和生活型的区别。
硫(S)属于气相型循环。( )
下列选项中是群落发育过程中良好发育这一阶段的主要标志的是( )
由于种群内个体间竞争而产生的种群分布是（ ）
有关数量金字塔的叙述正确的是（ ）
动物对冷环境的适应最直接的方式是 ( )
陆地生态学和水域生态学的划分标准是（ ）
热门试题
1.
处理那些已经达到白热化、不可能在短时间内彻底解决的矛盾与冲突时，更适宜釆取的协调方法是
2.
3. Friction is a force which opposes motion. Much of the energy supplied to a complicated machine with many moving parts is wasted in overcoming this opposition. The energy is converted into useless heat. The amount thus lost can be considerably reduced and the life of the machine prolonged by careful lubrication. This reduction improves the efficiency of the machine. Another way in which friction is reduced is to substitute roller or ball bearings for the earlier type of bearing, in which the surfaces in contact move by sliding. Bearings of these later types are used very extensively in many kinds of modern machinery.It must not be assumed, however, that friction is always a disadvantage. In many instances it is highly important. Belts are often used in conveying power from one machine to another. In the absence of friction, this could not be done. The driving wheel would not run the belt, neither would the belt run the wheel to driver. Without friction, then, belted machinery could not be used. Again in the case of all motor vehicles, friction is essential in the operation of the brake. Were there no friction, there could be no brake. But even this illustration does not give an adequate picture of the importance of friction. The vehicle could not even be started if it were not for the friction exerted between the tires and the road. Nails hold in wood, and screws hold in either wood or metal by reason of friction, without which they would be useless. Walking is difficult enough on an icy pavement, but it would be wholly impossible if there were no friction at all between the shoe and the pavement.(5分)3.1 Friction arises when____.(1分)A. an opposing force of motion exists B. the energy is wastedC. everything is motionlessD. a complicated machine is supplied with energy
3.
在考生文件夹下，完成以下操作：
4.
5.下列功能中，不属于企业资源规划（ERP）系统实现的是
5.
44. “‘Is dying hard, Daddy?’‘No, I think it’s pretty easy, Nick, It all depends.”’Questions:A. Identify the work the author.B. What was Nick preoccupied with when he asked the question?C. Why did the father add “It all depends” after he answered his son’s question?
热门试卷
成人高考专升本《政治》模拟试卷
去做题
已有3410做题
2020年湖北成人高考专升本政治模拟试题三
去做题
已有2205做题
成人高考专升本政治考试模拟试题及答案(1)
去做题
已有1893做题
湖北成考专升本政治真题（2021年）
去做题
已有1324做题
成人高考高起点语文考试高分突破试题及答案四
去做题
已有1189做题
