为什么是there are something to do而不是to be done

为什么是there are something to do而不是to be done something should be done to do对吗 Do you have something to be typed?为什么要用to be done的形式? in the school there are _____rules to be kept.为什么是填hard而不是en in the school there are _____rules to be kept.为什么是填enough而不是 为什么是be busy doing而不是be busy to do There be sth to do?和There be sth done? have something to do与have something to be done 的区别 the teacher wants the work（）at once.为什么是to be done 而不是 doing There are a lot of things to be done . 为什么是there is something wrong而不是there are something wrong with some homework to do为什么不是to be done