There ___ a pen and two pencils on the desk.用is还是are~

There ___ a pen and two pencils on the desk.用is还是are~ there is a pen and two books on the desk.还是there are a pen a Here is a pen and two pencils on the desk. There is a book,two pencils and a box on the desk.请问用There i 请问:There ____ a pen and two pencils in the bag.填is 还是 are 急 There ( )an Englisn book and two pencils on my desk .用is还是 a 18.There _____ a pen,two pencils,and three books on the desk There ( ) a pen and ( ) pencils ( )on the desk. 是there is 还是there are one pen and two pencils in the box There is a pen and two books on the desk.改为一般疑问句后be该用单数还是复数? There are a book and two pencils on the desk.改错 There is a pen and three apples on the desk.为什么用is不用are?