成群结伙的年轻人昨天在城里横冲直撞。Gangs of youths went on the rampage in the city yesterday.孩子们喜欢成群结伙相互攻击.Children like to gang each other.成群结伙愤怒的年轻人朝警察投掷石块。Groups of angry youths hurled stones at police....
It is also worth tagging on an extra day or two to see the capital.为了看看首都，再多个一两天也是值的。Professor Orr has developed interesting ways of tagging chemical molecules using existing laboratory lasers.奥尔教授发明了用现有实验室激光设备给化学分子做记号的种...