Translation of "Backpack" in Chinese

Or simply put it in my backpack.

或者干脆把它放在背包里

Inside my backpack there are many colored pens, red ones, blue ones, green ones, etc.

我的書包裡有很多彩色筆，紅的，藍的，綠的，等等。

After that, I left, but then I realized that I forgot my backpack at their house.

接着，我走了，但我意识到我把包忘在他们家了。