关系式x≤-5或x≥5所对应的布尔表达式是【 】。
参考答案：x＜=-5 Or x＞=5
解析：表示逻辑或的关系运算符号为Oro
Generally speaking, according to the directions,the drug has no side effect.
A．when taking
B．when taken
C．when to take
D．when to be taken
最常见的原发恶性骨肿瘤是（）
A.骨肉瘤
B.骨纤维肉瘤
C.软骨肉瘤
D.脊索瘤
E.骨髓瘤
