1. informal adj.非正式的(反义词__________) 1) 非正式谈话__________________ 2. serious adj.严肃的,认真的(副词_________) 1)你这么说是开玩笑还是认真的? ______________________________________ 2)认真对待…._________________________ 3. confidently adv. 自信地 4. lack v. 缺乏，缺少 1)He lacks courage to do it.________________ 2)lack sth.=_____________________. 3)用做n。常于of搭配 lack of sth________ The plants died for lack of water.__________ Lack of fund forced the firm to closedown. _______________ 缺乏常识。_______________________ 由于缺少经验，实验失败了。_______________________________

formal

an informal conversation

seriously

Are you joking or serious by saying so?

take sth seriously

be short of…

缺乏某物

这些植物死于缺水。

缺乏资金使公司倒闭

Lack common sense

The experiment failed for lack of experience.