题目

Philip was a nine-year-old boy in a Sunday school class of 8-year-old girls and boys. Sometimes the third graders didn’t welcome Philip into their group and usually tricked him. This was not because he was older, but because he was “different”. You see, Philip suffered from a condition called Downs’s Syn to each child. On that beautiful spring day, the children were to go out and discover for themselves some symbol of “new life” and place it inside the plastic eggs.     After the children returned to the classroom, the teacher opened their eggs one by one, asking each chi下列不等式：①x2+3＞2x（x∈R）②a3+b3≥a2b+ab2（a，b∈R）③a2+b2≥2（a-b-1）其中正确的个数有（　　）个．A、0B、1C、2D、3