fish可數(shù)還是不可數(shù)的由來

　　You need a licence to fish in this river.

　　你在這條河里釣魚要有許可證。

　　We enjoyed a day's fishing by the river.

　　我們在河邊享受了一天垂釣之樂。

　　In the wild, this fish can reach a weight of 5lbs.

　　這種魚在自然生存環(huán)境中可以長到5磅重。

　　Stand the fish tank on a firm base.

　　把魚缸放在牢固的基座上。

　　The fish return to the river as adults in order to breed.

　　這種魚長成以后回到河中產(chǎn)卵。