短语
单数形式
singular form
;
singsingular
;
stratum
;
kind
改成单数形式
Are these your balls
改为单数形式
These are new chairs
;
They are old men
;
Are these your books
;
Those are pictures of their families
谓语要用单数形式
the number of
以单数形式出现
man
写成了单数形式
three fourths
谓语用单数形式
one out of