If you cannot have a good command of grammar as well as precise usage of each word you’ve learnt, it is ________ for you to use English flexibly.
. One of the students hasn’t prepared lessons very well.
Either the boy or his sister must have dinner here.
He bought three books, is in Chinese, in English, and in Japanese.
stop fooling, boys and girls, and he .
To pay to see that movie will be foolish when you can see it on television for .