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 Mary,

    I receive your E-mail just now. Don't worry about me. I'm getting on well with my research work in the lab. But to my greatly surprise you say you will give up learn English. The reason is because you have not done well in it recently and you have lost interests. I'm afraid I couldn't agree with you . I know it is difficulty to learn English, and English is widely used in the world today. It will be important tool in our future work. Beside, it is becoming more and more important in our daily life. If you study hard, you will be succeed. Do remember that where there is a will, there is a way. I' m looking forward to hearing good news from you.

Yours,

Li Hua

在三棱锥$P-ABC$中，$PA=PB=PC$，底面$△ABC$是正三角形，M、N分别是侧棱PB、PC的中点．若平面$AMN\perp$平面$PBC$，则平面$AMN$与平面$ABC$所成二面角（锐角）的余弦值等于(      )

平面直角坐标系中，若平移二次函数y=（x-2009）（x-2010）+4的图象，使其与x轴交于两点，且此两点的距离为1个单位，则平移方式为（      ）