lts necessary to还是 for

lts necessary to还是 for lts necessary to还是for lts necessary to study geography at school Necessary+for还是to? necessary 后面是跟to 还是for? 是it's necessary for us to sleep for 8 hours 还是is' necessary for us to sleep 8 hours? an necessary application 还是a necessary application be necessary for和 be necessary to的区别老师说be important to后面加人,如果还有下文用be important for sb doing sth那be necessary to 和be necessary是不是也是这种用法?还是说be necessary to do sth be necessary for doing st I think it necessary to do sth.还是 I think it is necessary to do sth.如果是前者,为什么从句中不要be动词? To be taken when necessary. Do you think it necessary for me to give him a letter 这句话为什么不用is不应该是it is necessary .还是有什么额外的规则? an necessary application还是a necessary applicationthanks a million be necessary for和be necessary to 有何区别 necessary I find it necessary to know more about other countriesit necessary 不应该是it's necessary. Is it the telephone that lts us talk to people [from] all over the world这个from为什么不是about The weather is cloudy.It is ______ to take an umbrella with you.(是necessary还是unnecessary) ______,is it necessary for us to form the habit of reading every day.用such还是therefore?