李美今年十岁,体重26千克,他的标准体重是28千克,实际体重比标注体重轻百分之多少,

粗心的李美忘记在积里点上小数点,则他的得数是正确得数的10倍,因为他的得数比王祥的正确得数多出了7.2,所以正确的得数是7.2/（10-1）=0.8

解题思路：（1）电阻是导体本身的一种属性，与材料、长度、横截面积、温度有关，与导体两端的电压和通过的电流无关；（2）欧姆定律的内容：一段导体中的电流跟这段导体两端的电压成正比，跟这段导体的电阻成反比．

电阻是导体本身的一种属性，与两端的电压和通过的电流无关，而R=
U/I]、R=
U2
P、R=
Q
I2t都是计算电阻的方法．
故选D．

点评：
本题考点： 欧姆定律的变形公式；影响电阻大小的因素．

考点点评： 知道影响电阻大小的因素，并且知道导体的电阻与导体两端的电压和通过的电流无关，但可以根据欧姆定律计算出电阻的大小．

Dear MOm and Dad,
I have took part in a English-studing class in London during this holiday.I've arrived here about a week.Everyday we study English and we can help each other.London is a really beautiful city,but the weather is very terrible.You can live in four seasons in a day.Sometimes it's warm and wet,but sometimes it's cold and dry.However,you needn't worry about this,because I can look after myself very well.
Our classmates are very friendly,they often help me in my English.We often do sports.They come from different countries but all of us talk in English.I really have a good time in London.
Best wishes.
Yours,
limei
如果是七年级的英语作文这样也就可以了,希望采纳,谢谢!

Dear mumand dad:
I have been arriving at shool a week.i had a good time here.we talk in Englishat school,and sometimes we do s[ports in the morning.London is a big cityand the weather is changeable,so people in London always have an umbrella with them.Our classmate was very fridenly.they come from different countries ,but there was a time that we got along well.they can help me when I got in trouble.I like my life in London.
YoursLi mei
Li mei

少点一位小数点,因此就是正确答案的10倍,比正确答案多了10-1=9倍,
正确答案是7.2÷9=0.8
正确的积是0.8 (验算:错误的是8,8-0.8=7.2)