两个角大小的比为7：3，它们的差是72°，则这两个角的数量关系是 [ ]
A．相等
B．互补
C．互余
D．无法确定
答案：B
He had been________absorbed in watching the car passing by that he didn't notice his friends coming.[ ]
A. such
B. too
C. that
D. so
急性白血病的共同特征描述中错误的是（）
A.发热和感染
B.贫血
C.出血
D.全身浸润
E.黄疸
