在空白处填入一个适当的词，或填入括号中所给单词的正确形式。
You may have heard of
Niagara Falls（尼亚加拉大瀑布), but do you know
about the Niagara Escarpment(断崖)?It's a long steep
slope(陡坡){#blank#}1{#/blank#}runs
through the US and Canada. Earlier this month, our school went on a hiking trip
to this beautiful place.
The weather was cold, cloudy
and windy, so we wore more{#blank#}2{#/blank#}(stay)warm.
We{#blank#}3{#/blank#}(divide)into
two groups and went on different routes(路线).
The whole escarpment is 725km long. But we only covered 8km for about four{#blank#}4{#/blank#}(hour).
My favorite part of the
trail(dx道)was the cave(山洞). The
cave was formed from many different shaped rocks. Some were huge while the{#blank#}5{#/blank#}were small. We climbed down into the
rocks{#blank#}6{#/blank#}the
help of our teachers. The rocks were steep and slippery(滑的)because they were wet. It was{#blank#}7{#/blank#} exciting experience for all of us.
After{#blank#}8{#/blank#}(walk)5 km without any rest, we were
hungry and tired. {#blank#}9{#/blank#}our teacher finally said we could stop to
have lunch, we were very excited. After all, this trail was a little different
from the ones I'm used to. It was{#blank#}10{#/blank#}(natural)than
before.
