explain/ ɪks'pleɪn /

1.vt.[+situation] [ contract] 
(make understandable) 解释

2.vt.[+decision] [ actions] 
(give reasons for) 阐明

to explain why/how {etc}
解释为什么/如何{等}
to explain sth to sb
向某人解释某事
to explain that...
解释…