听力原文

Back in the roost, the young are left on their own. Special pads on their wings help them to grip on the bamboo walls-most of the time.
小家伙们被留下来看家。翅膀上独特的肉趾帮助他们攀爬竹壁，绝大多数时候。
The young bats use the extra space to prepare for a life on the wing by preening and stretching.
小竹蝠们在剩下的空间里用伸展腰肢整理翅膀为日后的飞行早做准备。
Packed in like sardines, they would make an easy target for a snake.
就像罐头里的沙丁鱼挤得满满的，将成为容易被蛇攻击的目标。
But the snake has no chance of getting in. The entrance is thinner than the width of a pencil.
但是蛇却没有收获的机会。入口的宽度比铅笔还要细。
When the mothers return, they can push through the narrow entrance only because of their unusually flattened skulls.
当蝙蝠妈妈回来时，穿过狭窄的入口必须要依靠它们与众不同的扁平颅骨。
But it's still a squeeze. Bamboos are exploited in a very different way by another forest dweller. Fresh bamboo shoots are an important forest crop.
同样还是需要用力才能挤进去。另一个深林的原住民在竹子的采集与使用方面独辟蹊径。新鲜的竹笋是重要的深林作物。

重点讲解

重点讲解：
1. on one's own
单独地；独自地；
eg. I need some time on my own.
我需要独处一段时间。
eg. For many old people living on their own the telephone is their lifeline to the outside world.
对许多独居的老年人来讲，电话是他们与外界联系的生命线。
2. push through
通过；穿过；
eg. The doctor pushed through the crowd to get to the injured man.
医生挤过人群来到受伤的男子面前。
eg. The hole is too small; I cannot push my arm through.
这个洞太小了，我的胳膊伸不过去。
3. because of
因为；由于；
eg. Many beautiful fish are fast disappearing because of the severe pollution.
因为污染严重，许多美丽的鱼类正在面临绝种。
eg. He got angry with me because of my remark.
他由于我讲的话而生我的气。