Trapped turtles can often free themselves 被困住的海龟在涨潮的帮助下
But free riders are only tolerated for so long. 不过搭便车的也得意不了多久
wriggle free and drop into the stream below. 可以扭动着挣脱出来 掉进下方的溪流里
but it's still a struggle for the flamingos to break free. 但是火烈鸟仍然需要努力冲破冰层
if it can't free itself,the youngster will starve. 如果它摆脱不了 就会饿死
lemurs have been free to colonise almost every environment on the island, 狐猴能够在整片岛屿上生活
The ducks must quickly prise the mussels free before the tide starts to turn. 绒鸭必须赶在潮流转向之前迅速采食
less than three per cent of Antarctica is free of ice, 南极洲也只有不到3%的地方没有被冰封