In school all over the world,boys and girls are learning foreign languages.Everyone knows his o___ language,but a____ is

In school all over the world,boys and girls are learning foreign languages.Everyone knows his o___ language,but a____ is very useful.If we go to england or usa,we s___ be able to speak english.And in japan people will wish us to u___ japaness.
How many languages are there in the world?there are about fifteen hundred,but many of themare not very i______.English is one of the most important l____ because so many people use it,not only the england and the usa but also in o___ parts of the world.About two hundred milion people speak it as their own language and more use it as a s____ language.It is d___ to say how many people are using it.Many milions of schoolboys and schoolgirls are t___ to use it,too.So try you best to learn english well.
我主要看第二个和最后一个