7. a great / good many许多
(1) a great / good many 名词复数，中间无“of”。A great many people have seen the film.
(2) a great / good many of the / these / those / one's 名词复数 A great many of the people have seen the film.
8. make yourself at home 别拘束
(1) make yourself at home 别拘束(主人对客人说的委婉语) -- Good evening, Jim. -- Good evening, Mary. Come in and make yourself at home.
(2) (all) by oneself 独自(没有别人帮助) You can't possibly do it all by yourself.
(3) enjoy oneself = have a good time 玩得高兴 Please enjoy yourself while you're spending your holiday in Hawaii.
(4) for oneself 亲自; 为自己The student wants to think it for himself. / One should not live for oneself alone.