1.  When I saw t, I said it was easy, and I had done it.

2.  This isn't easy.

3.  some question is very easy to answer for us.

4.  sometimes, some question is very easy to answer or us .

5.  If you that, I think you will learn English very, and find it easy .

6.  I think you must say "yes ", because this song is very popular and common on birthday and it's easy for us to sing.

7.  there are so many popular song which are liked by young people now, I like the songs too ,but I don't think those will be popular forever, this song" happy birthday to you is my favourite song, perhaps you will be asked me: "it's too easy and simple, why do you like it ?"

8.  it's easy to learn and easy to understand.

9.  it wasn't easy.

10.  I forgot the words very easy , and I didn't remember again in time.