13.(poor)不精通的；不擅长的；弱的；差的
Geography was my weak subject.地理是我的弱项。
the relatively weak performance of girls in maths and science女孩在数学和理科课程方面相对较弱的表现
14.(unconvincing)+ argument缺乏说服力的；不能令人信服的
The evidence against him was weak.指控他的证据不足。
15.to be weak on sth
(lack strength in certain area)在某方面较差
His short stories tend to be weak on plot.他的短篇小说往往情节牵强。
16.【语法】+ verb弱变化的(即动词变位靠词尾变化, 而非内部元音改变, 如：look, looks, looking, looked)
17.【语法】(regular)(任何词类)规则变化的