there be结构中,be的选用要看后面名词的单复数形式决定,最靠近的那个名词,就所谓的“就近原则”
There (is ) a little snow on the ground
there（are ）three birds in the tree
there (is )an eraser and two pencils in my pencil case
there ( are ) two pencils and one ersser in my pencil case