如果两个数的积为负数，和也为负数，那么这两个数（ ） A．都是负数 B．都是正数 C．

Do you know that man? He is my uncle. His n_____小题1:is David Smith. He’s 40 this year. His j____小题2:is a worker. He works in a car f_____小题3:. His factory is not n____小题4: his home. So he gets up early in the morning and t_____小题5:a bus to work. At about 7:30, he gets to his factory. He m______小题6: the parts (零件) of the car. He works very hard. Everyone likes h____小题7: and says he is a good worker. He has lunch in the factory. He often plays b_____小题8: after work. In the evening, he u_____小题9: learns Chinese at home. His Chinese is good, too. Sometimes he h_____小题10:me with my Chinese. I like my uncle very much.

牙髓息肉

A．又称慢性牙髓脓肿

B．主要表现为慢性炎症性牙髓组织的过度增生

C．表面均有上皮覆盖

D．患牙一般无穿髓孔

E．多发生于切牙

患者，男，全身面积烧伤55%，近日来常寒战、高热，呈间歇热，四肢厥冷，发绀，尿量明显减少。很快血压下降到70/50mmHg。其原因最大可能是（）。

A.革兰阳性细菌败血症

B.革兰阴性细菌败血症

C.真菌性败血症

D.厌氧菌性败血症

E.二重感染

使用百分比抽样方案对某产品进行验收，规定抽取比例为1%，接收数为A=0，当交检批质量水平为10%时，可求得：

根据以上结论可知，百分比抽样分案（）。

A.在批质量相同时，大批严小批宽

B.在批质量相同时，批量越小使用方风险越大

C.是一个科学的抽样方案

D.只要控制批量，就可以避免百分比抽样方案的缺陷

E.要制定合理的百分比..

扣件式钢管模板支架的梁下支撑立杆，应与梁侧及板下立杆之间设置贯通的（）。

A.竖向、水平剪刀撑

B.连墙件

C.纵、横向水平杆

D.双立杆