选择可以替代下列划线部分的最佳选项或句中划线部分的最佳解释。

I don't know why you have no business to do that.

[　　]

　　Today is March 7th, and tomorrow is 1 . Doris wants to 2 her mother a gift. She 3 10 dollars. She is thinking about 4 buy. She thinks and thinks. Then she has 5 idea（主意）.“I can buy a card 6 my dear mother.”

　　Doris goes to a supermarket and buys a beautiful card. She 7 some words on it.

　　She shows it to her mother and says,“Here is a card for you, Mum.”Her mother is 8 happy.” 9 , Doffs.” She says. Doffs is 10 , too.

找出下列句中的错误并改正

Because English is important, so we should learn it well.

　A　　　　　B　　　　　　　　　　　C　　D