改否定句、疑问句、肯定句,有没有什么好的方法?

改否定句、疑问句、肯定句,有没有什么好的方法?
改否定句、肯定句
1 we were happy at Christmas.肯定
2 I was sad this morning.否定
3 You must keep quiet in the hospital.肯定
4 They must go home now.否定
5 we shall go to the cinema this summer holidy.肯
6 They can blow bubbles.否
7 He has breakfast at 7:00a.m.every day.肯
8 She does the housework at weekends.否
9 The studentsdo some reading after class.肯
10 Sue and May often go skating.否
11 Jenny looked after her little sister at home yesterday.肯
12 Jack cut the cake into six piece just now.否
13 yhe students stopped talking when their teacher came in.肯
汉译英：
你最喜欢哪个城市,上海、广州,还是北京?
你姐姐是医生还是教师?
你通常是在11点还是在12点吃午饭?
你在哪个班级,一班还是二班?
这是谁的猫,他的还是她的?
你想吃什么?三明治还是汉堡包?
根据实际情况回答问题：
how often do you have a P.E lesson at scool?
when is your birhday?
how much is your schoolbag?
what day is today?(这题目好像出错了）
what clothes are you wearing?
Which is your favorite city,Shanghai,Guangzhou,or Beijing?
Your sister is a doctor or a teacher?
You usually at 11:00 or at 12:00 for lunch?
Which class are you,a group or a second class?
Who is this cat,his or her?
What do you want,sandwiches or hamburgers?
复制下题目,抄题
好吧……能答多少答多少,我追分

根据实际情况回答问题：
how often do you have a P.E lesson at scool? once a week.
when is your birhday? August 1st.
how much is your schoolbag? CNY 1800.
what day is today?(这题目好像出错了）Tuesday.(没错,这个是问星期几,what day is it today是问几号)
what clothes are you wearing?t-shirt.
这个对吗?-- 错的改掉了,其他都可以的.
Which is your favorite city, Shanghai, Guangzhou, or Beijing?
Your sister is a doctor or a teacher?
You usually at 11:00 or at 12:00 for lunch? -- 没动词.you usually have lunch at 11 or 12?
Which class are you, a group or a second class?--少了个介词,如果按你写的把它变成陈述句就是you are which class,检查对不对可以变成陈述句看看,陈述句比较容易看出问题.which class are you in, Class 1 or Class 2?
Who is this cat, his or her?-- 同学,你写的陈述句会变成this cat is who（这只猫是谁,而不是“谁的”,谁的应该用所有格的疑问代词whose,后面的应该用his/hers名词性物主代词）,应该是whose cat is this, his or hers?
What do you want, sandwiches or hamburgers?
前面的改否定肯定句真心没看懂,后面的肯定否定是什么意思.
再问： 比如这个：1 we were happy at Christmas.肯定，就是这句话改肯定句
再答： - - 问题是这就是肯定句呀。。。怎么改。。。
再问： must不是肯定么？就用这个什么的
再答： 很多都是肯定句为什么还要继续改肯定句。。没有否定词不就是肯定句么，原题要求就是这样？ 1 we were happy at Christmas.肯定 - we must be happy at Xmas.（你说的是这样？） 2 I was sad this morning.否定 - i wasn't sad this morning. 3 You must keep quiet in the hospital.肯定 - 对不起我不会。。 4 They must go home now.否定 - they mustn't go home now. 5 we shall go to the cinema this summer holidy.肯 - 改不出来。。 6 They can blow bubbles.否 - they can't blow bubbles. 7 He has breakfast at 7:00a.m.every day.肯 - 还是不会。。 8 She does the housework at weekends.否 - she doesn't do the housework at weekends. 9 The studentsdo some reading after class.肯 - 完全不会改。。 10 Sue and May often go skating.否 - sue and may don't go skating. 11 Jenny looked after her little sister at home yesterday.肯 - Jenny must look after her lilttle sister at home yesterday.(按你说的，改成这样的意思？) 12 Jack cut the cake into six piece just now.否 - jack didn't cut the cake into six pieces just now. 13 yhe students stopped talking when their teacher came in.肯 - 我错了。。我真不会
再问： 嗯哪，已经交过了，谢谢（后来老师说题目不对，(*^__^*) 嘻嘻……）