问题 问答题 简答题

什么是寄乳,如何进行寄乳?

答案

参考答案:

寄乳:就是将仔犬给养给其他哺乳母犬的一种方法。

寄乳前先将保姆犬的乳汁或尿液涂在欲寄乳仔犬身上,使其带有保姆犬同样的气味。刚开始接触时,应观察与管理,防踩咬现象,必要时可戴上口套,待其允许仔犬吸乳后再摘下。

断奶:一般45日龄可以断奶。

阅读理解

阅读下列材料,然后根据材料回答所提问题。

     Most of middle school students always wear school uniforms when they are at school, but they also want

to make themselves look fashionable and nice. They can't make money now. Is it necessary for them to wear

labels (品牌)? Some students show us their own opinions.

Bill:

     I get new clothes and shoes quite often. My parents buy them for me. I buy things because I like them. I

get angry if I don't get what I want. I think it's important to wear labels. My favorite lable is Nike because it's

the best maker I think.

Kate:

      My mum buys me clothes and shoes. On birthdays I buy my own. I always go for labels because they

make me look in fashion. But I don't think it's important to wear labels. I buy things because I like them, not

because of the price or the label.

Paul:

     My mother buys me clothes. I don't think labels are important. But my favorite label is Adidas. And I

sometimes can't get the things I want because my mother can't afford them. I just wait until she has enough

money.

1. What do most of students wear at school?

____________________________________________.

2. Who buys new clothes and shoes for Bill?

____________________________________________.

3. When does Kate can buy her own clothes?

____________________________________________.

4. Is Nike Paul's favorite label?

____________________________________________.

5. What will Paul do if his mother can't afford the things?

____________________________________________.

填空题

在“探究求合力的方法”实验中,现有木板、白纸、图钉、橡皮筋、细绳套,某同学还找来了实验室里常用的几种弹簧秤.如图所示.

(1)为最准确完成实验,在做实验时最合理的是选择______图弹簧秤?(填写“甲”、“乙”、或“丙”)

(2)在实验中,需要将橡皮条的一端固定在水平木板上,另一端系上两根细绳,细绳的另一端都有绳套(如图丁).实验中需用两个弹簧秤分别勾住绳套,并互成角度地拉橡皮条.某同学认为在此过程中必须注意以下几项:

A.两根细绳必须等长.

B.橡皮条应与两绳夹角的平分线在同一直线上.

C.在使用弹簧秤时要注意使弹簧秤与木板平面平行.

其中正确的是______.(填入相应的字母)

(3)若在实验中,把木板竖直放置,同时用细绳OA跨过钉在木板上的光滑的钉子C,下端挂重力已知的钩码,细绳OB用一个弹簧秤钩住,如图丁所示,可以通过改变钩码的个数和弹簧秤的拉力调整橡皮筋与两细绳的结点O的位置.图中OC与橡皮筋延长线的夹角为α,细绳OB与橡皮筋延长线的夹角为β,且α+β>90°,下列操作正确的是______

A.增加钩码个数后,为使结点位置不变,应减小β,同时减小弹簧秤的拉力

B.增加钩码个数后,为使结点位置不变,应增大β,同时增大弹簧秤的拉力

C.保持钩码个数不变,将钉子C向左移动一些,为使结点位置不变,应增大β,同时增大弹簧秤的拉力

D.保持钩码个数不变,将钉子C向左移动一些,为使结点位置不变,应减小β,同时增大弹簧秤的拉力.