英语听力：自然百科 鲨鱼湾的海豚—7

 Puck needs to watch out.As she searches in the sea grass,she will be unaware¹ of any shark approaching.If a tiger shark closes form behind,her sonar can not detect it.Distracted,Puck could be easily attacked.Once detected,Puck can easily out swim the shark.But when her calf² arrives,it won't so easy for her to escape.it gets very shallow here,this is the low tide too. Dxxgangs,Mother and a calf.

Look at this little baby,look at that.More than 10000 G living shark bay.it is the largest population in the world,Grazing on the grass beds,they are the most vulnerable to shark attacks,in the shallows they have less room to manoeuvre³.

The calf swims on top of his mum,that way it is protected from the sharks,which could make a good meal of a  Dxxx calfm.

Much swim slower than the dolphins,thousands of D calves⁴ are taken by the sharks every summer.We got dolphins and D together here,Hey,Puck.Oh,you are wide.

Looking for clues as to when Puck might give birth,J lowers a special microphone into the water.

1 unaware   

a.不知道的，未意识到的

参考例句：

• They were unaware that war was near. 他们不知道战争即将爆发。
• I was unaware of the man's presence. 我没有察觉到那人在场。

2 calf   

n.小牛，犊，幼仔，小牛皮

参考例句：

• The cow slinked its calf.那头母牛早产了一头小牛犊。
• The calf blared for its mother.牛犊哞哞地高声叫喊找妈妈。

3 manoeuvre   

n.策略，调动；v.用策略，调动

参考例句：

• Her withdrawal from the contest was a tactical manoeuvre.她退出比赛是一个战术策略。
• The clutter of ships had little room to manoeuvre.船只橫七竖八地挤在一起，几乎没有多少移动的空间。

4 calves   

n.(calf的复数)笨拙的男子，腓；腿肚子( calf的名词复数 )；牛犊；腓；小腿肚v.生小牛( calve的第三人称单数 )；（冰川）崩解；生（小牛等），产（犊）；使（冰川）崩解

参考例句：

• a cow suckling her calves 给小牛吃奶的母牛
• The calves are grazed intensively during their first season. 小牛在生长的第一季里集中喂养。 来自《简明英汉词典》