Dear Mr/Ms Jiang
I was unable to come to 1st and 2nd period today.Due to the rain yesterday, I was wet and had temperature at night. The doctor adviced me to rest for several days and after my recovery, I will attend school as soon as possible.
I am sincerely sorry about the inconvenience. However, I would like to have your permission. Also, afterwards I would phone you and there's the certificate by the doctor.
Li XX
October 21st 201X
译文
我叫李XX，20XX年10月21日向英语老师江老师请假。
内容：由于感冒今天不能来上1，2节的英语课。昨天淋了雨。晚上发烧，医生建议休息一两天，身体恢复后会立即去上课。请批准为盼。英语课结束后会给老师打电话。附上医生的证明。
Dear Mr/Ms XXX;
Today I'm writing to you to ask for a five-day leave, for I've got cold last night with carlessness.
This morning my mother took me to see the doctor,who told me to stay in bed for some days. So I am very sorry to be absent from school, especially your interesting lessons. I'll be sure to make up for the missed lessons after I recover from the illness.
Yours ever,
XXX.
译文：
尊敬/亲爱的XXX;
我今天给您写信是要请5天的假，因为我昨天晚上不小心感冒了。今天早上，我妈妈带我去看了大夫，大夫告诉我要在家里躺几天。所以，我对缺颗，特别是不能上您那有趣的颗，感到难过。我病好后一定把漏掉的课程补上。
此致
敬礼。
您的学生：XXX.