英语阅读完形填空(首字母已给出）

Nowadays more people cross the ocean in planes than in ships.Are plans taking the place of ships?No.Ships are (still )ecessary.They carry cargo all over the wrold.The cargo may be cars.It may be grain.It may be animals.A ship can carry hungrys of tons of cargo at one (time ).A big plane can carry about 50 tons of cargo across the ocean.
In the 1850s,fast American clipper ships sailed across the seas.Furs (from ) this country were sent to China.From China,the clipper ships brought (both )silk and tea.Then steamships (took ) the place of clipper ships.