我很失望。

(我覺得不用太改你的句子,只是想也許你會想看看換個寫法,但表達方式很多啊)　

今天我感到很失望， 因為我收到了上個月的漢語考試結果， 我得到99分。

-->我今天收到上個月的漢語考試成績，我很失望因為我只考了99分。

老師說我失一份因為我說“你應該好好休息吧。”

-->老師說，我被扣一分是因為這個句子“你應該好好休息吧。”

-->老師說，因為這個句子“你應該好好休息吧。”我被扣一分

 她說在漢語裡，你們不能用'應該'和'吧'在一個句子裡一起使用。

--->她說在漢語裡，'應該'和'吧'不應該出現在同一個句子裡。

我總是說’應該。。吧'。 沒人對跟我說這是錯的。真的不能同时時使用嗎？

I think it sounds more like asking a question/ or offering a suggestion when you put 應該and 吧in one sentence. So in this sentence “你應該好好休息吧。”I would imagine someone has been stayed up late for a whole week, so you say  “你應該好好休息吧?!”. It also imply you don't really agree the way that person doing things(stay up late for a week)

你應該沒問題吧?--->you can manage the situation, right? (asking a question)

I have never learned grammer this kind of stuff, so it's just 我的直覺, not sure it's right or wrong! Well, 99 percent was pretty good!

I am very disappointed today because I received the results of last month's Chinese exam, I got 99 percent. The teacher said I lost a point because I said, "你應該好好休息吧." She said in the Chinese, you can not use 應該 and 吧 in a sentence together. I'm always saying 應該。。吧. No one has told me this is wrong. You really cant use them at the same time?