原发性恶性骨肿瘤中,临床发病率最高,超声检查发现最多,恶性度最大的肿瘤:
A.成骨肉瘤
B.软骨肉瘤
C.滑膜肉瘤
D.纤维肉瘤
E.骶尾部脊索瘤
参考答案:B
笔名、艺名都属于姓名权保护的范围。[ ]
—________ he often go to school by bike?
—No, he ________. [ ]
A. Is; isn't
B. Do; don't
C. Does; does
D. Does; doesn't