这里的的face为什么要加ing?求教The biggest safety threat (facing) airlines today may not be a terrorist witha gun,but the man with the portable computer in business class今天飞行航线的最大的安全威胁不是带枪的恐怖分子,

求教do you remember meeting me in Beijing?请问这里的meet为什么要加ing? 这里的come为什么要加ing 为什么这里的play要加ing形式 这里的的face为什么要加ing?求教The biggest safety threat (facing) airlines today may not be a terrorist witha gun,but the man with the portable computer in business class今天飞行航线的最大的安全威胁不是带枪的恐怖分子, 这里的EAT为啥要加ing one of the biggest problen facing people is ````````这里的face 为什么要用ing形式啊 Is it working这里的work 为什么加ing. 为什么Thanks for inviting me.为什么这里的invite要加ing we have a new family joining us today,这里的join为什么要加ing? Do you like playing chess?为什么这里的play要加ing? My father likes playing volleyball in the morning.为什么这里的play要加ing Life is all about making connections 这里的make为什么要加ing? A good beginning is half of success 这里的 begin 为什么 要加ing Does your mother like watching movies?这里的watch为什么要加ing? Anyone having any problems about this question...请问这里的have 为什么要加ing? just finished,and finishing up things for tomorrow这里的finishing 为什么要加ing哦 将they改成we的话要加ing,那——They don't like set the table这里的set要不要加ing? visit加ing的时候为什么不是双写t加ing呢