5. A good climber would have professional climbing gear.
登山好手要有一些专门的登山工具。
还能这样说：
To be a good climber, you need professional climbing gear.
As a good climber, one should have professional mountaineering equipment.
应用解析：
hunting gear 打猎用具;
party gear 宴会的衣服;
put into gear 开动机器;着手工作;
gear up 挂快挡;加速
6. It's not a difficult climb.
这次攀登并不难。
还能这样说：
Climbing mountain is not so difficult.
The mountain is not hard to conquer.
谚语：
Nothing is difficult to a man who wills.
世上无难事，只怕有心人。
7. We now set out to climb the mountain.
这时我们开始爬山。
还能这样说：
Now we begin to climb the mountain.
We start to go mountain-climbing.
应用解析：
get set 预备开始;
set forth one's views 阐述己见;
set by 把……搁在一旁;
set free 释放;解放;
set in one's attitude about 抱定自己对……的态度
8. He dropped behind when we were climbing the mountain.
我们爬山时，他掉队了。
还能这样说：
He logged behind our team when climbing the mountain.
He dropped off when we climbed the mountain.
应用解析：
drop drinking 戒酒;
drop a hint 暗示;
drop sb. a line 给某人写封短信;
drop with fatigue 累倒了;
drop in on a friend 顺便走访朋友