题目

He can do what he can______ the children in his neighborhood.                   A. help                          B. to help                       C. helps 答案：B下列命题：①空集是任何集合的子集；②若整数a是素数，则a是奇数；③若空间中两条直线不相交，则这两条直线平行；④=2其中真命题的个数是（ ）A．1个B．2个C．3个D．4个