Students are sitting lined up on stair steps while they wait and check their electronic devices .
It is certain that there are several friends standing on the school stair and exchanging pictures from there electronice gadgets
It is probably not the case that there are several friends standing on the school stair and exchanging pictures from there electronice gadgets
It is certain that there are several friends standing on the school stair and exchanging pictures from there electronice gadgets
There are several friends standing on the school stair and exchanging pictures from there electronice gadgets