小佳姐～:)
你好~一定：certainly如果是要用在主语后面的那种，就是must，wemustxxx我们一定要certainly是用在回答的。以上由√似氺σ蓅哖为您解答！如有疑问，欢迎继续追问；如果对我的答案满意，请务必采纳~谢谢o(∩_∩)o
Dana是天枰座
一定：certain.
例句：
我一定会时刻睁大眼睛提防他的行为。
I shall certainly keep a beady eye on his behaviour.
这项工作必须在一定期限内完成。
The work must be completed within a certain time limit.
我觉得我们一定是在什么地方拐错了路。
I think we must have taken a wrong turning somewhere.
一定要找个宽敞地儿坐得舒服一点。
Make sure you have plenty of room to sit comfortably.
一定要确保所有的门都锁好了再走。
See that all the doors are locked before you leave.
薇儿的悲伤
需要用英语表示为：need，need英式发音为[ni:d]，美式发音[nid]。意思是：vt.需要；必须。aux.必须；不得不。n.需要；需要的东西；责任；贫穷。vi.（表示应该或不得不做)；有必要。
拓展资料
need的用法
1、He desperately needed money
他迫切需要钱。
2、The building needs quite a few repairs.
该建筑有好几处应该修缮。
3、Mr Forrest believes there is a need for other similar schools throughout Britain
福里斯特先生认为全英国都需要有类似的学校。
4、What is right for us need not be right for others
对我们来说是对的东西，对别人来说未必正确。
5、Mid-fifties, short black hair, grey moustache, distinctive Russian accent. Need I go on?
五十四五岁，黑色短发，灰色八字胡，明显的俄国口音，还需要我继续说吗？
6、The education authorities have to provide for children in need
教育主管部门得救助贫困儿童。
7、I was all right but in need of rest
我没事，就是需要休息一下。
8、They will now seek permission to take their case to the House of Lords, and, if need be, to the European Court of Human Rights.
他们现在将争取获准将案件呈交上议院审理，并且，如有必要，会上诉到欧洲人权法院。
汤糖躺烫湯
一定certain英[ˈsɜːtn]美[ˈsɜːrtn]词典fixedestablishedregular例句这项工作必须在一定期限内完成。The work must be completed within a certain time limit.
