All our efforts are of no effect,为什么要加of?

All of them are young pioneers为什么要加of? That the efforts of men and women are of no significance alo they are good friends of ours.our为什么加s 英语翻译In spite of our efforts,we seemed to be getting no close 英语翻译in spite of numerous efforts,we are unable to teace all 生物专业英语 求翻译In all aspects of biotechnology major efforts are There are many kinds of books in our school library.为什么加OF? one of the effect(s)~,要不要加S啊? Are you afraid of snakes?回答用Yes,not very还是No,not at all?为什么? all of./each of...后面加is还是are there are all kinds of troubles in our life、thing we are all just prisoners here of our own device