she's had to go to chicago on a business trip中she后面为什么用is ha

she's had to go to chicago on a business trip中she后面为什么用is ha she's had to go to Chicago on a business trip She is ( )(go)on a trip to Guiling next week. Where is Miss Wu?She (go) to England on business. She had to go to that school on a bike.为什么是had而不是has she had to go to that school on a bike. It said that she and Dad had to go out on business and my bo She (go)to America on business five times in 2011 our plan is to go on a study trip to London ,is to go on a s she is smart enough to go into business. 成分分析She is smart enough to go into business. She told me that she would go on trip to Europe the next day