how many of you have been to the usa?起什么作用

how many of you have been to the usa?起什么作用 how many of you have been to the usa?答句选什么 have you ever been to the USA how many of you have been to Canada? how many of you have been to the three corges dam?翻译 HAVE you been to the USA?(作肯定回答） How many times have you been to the Great wall?为什time要加s Have you ever been a___?yes,I have been to the USA before How many times have you been to Beijing? 翻译：HOW MANY TIMES HAVE YOU BEEN TO BEIJING? how many cities have you been to in china 中文 how many have you been here