文中共有10处语言错误。每处错误仅涉及一个单词的增加、删除或修改。增加：在缺词处加一个漏字符号（∧），并在其下面写出该加的词。删除：把多余的词用斜线（\）划掉。修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意：1.每处错误及其修改均仅限一词；2.只允许修改10处，多者（从第11处起）不计分。

Dear David,

    Sorry to learn that you've put on weight. Eat too much food in McDonald's and KFC must be the reason, I guess.

    You have to realize that food is not always as healthy as was said in the advertisements. If you know much about them, we will find fried chicken and French fries are rich in fat, sugar and salt. They can make you to gain weight and become sick.

    That you ought to have every day are noodles, rice, fruit and vegetables rather than the junk food. Energy-giving food, body-building food and protective food makes up a balanced diet. In word, you must have an idea of how a healthy diet should be and stick to it.

    I hope my advices can help you improve your health.

Yours,

Li Ming

等臂杠杆两端各系一只等质量的铁球，将杠杆调平衡后，将球分别浸没在等质量、等密度的稀H₂SO₄和CuSO₄溶液里（如下图所示），一段时间后杠杆将会（ ）