there aren't a pen and a book on the table为什么用and

there aren't a pen and a book on the table为什么用and There are a book and a pen on the table. There is a book and a pen on the table改为复数句 there is a book and two pen on the table just now. There( ) a pen and a book on the tabie . There ( )a book, some pens and magazines on the table there is a pen and some rubbers on the table.这里应该用is还是are? Three___a pen and four book on the table.a:is b:are There are some books,a pen and a pencil on the table,_______ Is there a pen and two books on the table?答句是什么? A pen and two watches are on the table There is a book and a pen on the desk.(变为否定句)