五、语法填空。
It was a common sunny January day. Silvia and Amira went to explore the mountains without telling their parents because they thought it was a good chance to show their parents the power 25. ______ courage. They walked a few miles. At lunchtime, they ate 26. ______ (sandwich) by a river. Then they walked 27. ______ (slow) along the river, enjoying the beautiful scenery.
But in the afternoon, clouds were appearing over 28. ______ top of the mountains and the rain was beginning to fall. To 29. ______ (they) surprise, the sky became very dark. It was almost as dark 30. ______ night. Even worse, Silvia and Amira found they were 31. ______ (lose). When there was a loud sound, the snow 32. ______ (move) off the mountains, causing an avalanche（雪崩）. Silvia and Amira knew they were in danger. They began 33. ______ (run) back down the mountains fast. Luckily, the avalanche was much 34. ______ (high) up the mountain. They arrived home safely in the end.

of
; sandwiches
; slowly
; the
; their
; as
; lost
; was moving
; to run/running
; higher