四、 克漏字測驗　　If you’re reading this article, maybe you’ve already ____21____ hours studying English. However, here are some facts you may not know about the language.
       English is one of the most ____22____ languages in the world. English has about 339 million native speakers. More than fifty countries have English as their official language. English is also ____23____ as the official language of the sky. That means all pilots use it on flights.
        English is close to German, but it uses many words ____24____ French. In fact, many other languages have been brought into English. Because of this reason, English has one of ____25____ vocabularies of all languages.    　 
  native speaker母語人士   official官方的   pilot飛行員   vocabulary字彙　
【題組】21.
(A) cost
(B) spend
(C) costs
(D) spent