good

I've got some introduction of Niagra falls in wikipedia,is the collective name for three waterfalls that straddle the international border between the Canadian province of Ontario and the U.S. state of New York. Thanks! I'm envious of your experience of whale watching! Qing

I wanted to say more,but I couldn't express well.

Easy to learn.

It's nice feeling.

Great! and the arrangement is satisfactory!

Need more simulation by mp3

feel good

多预习！

I did not prepare well before class