阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

My friends and I  (organize) a mountain-climbing on July 21-22. we took a bus for about 2 hours to arrive  the foot of Mount Hua.

At about 10 pm, we began to climb the mountain. It was dark and   (climb) the mountain was a little dangerous and tiring. , we were all excited (see) so many travelers climbing together with us. When some fell behind, would offer help. We all reached the top at around 5:00 am. How excited we felt to see the sun(rise) in our eyes. We jumped and cheered with great joy. At the top of the mountain, different kinds of (bird) were flying around us, and we could breathe fresh air (free).

The activity benefited us a lot. It is not only interesting but also (mean). What a happy time!