原发性高尿酸血症和痛风发病有关因素为
A．肾尿酸排泄减少
B．尿酸生成增多
C．嘌吟生成增多
D．肾嘌呤排泄减少
E．鸟嘌呤核甘酸生成增多
参考答案：A,B
On October, 6 Apple’s Board announced that Apple had lost ______ wise and creative pioneer, and his spirit would forever be ______ foundation of Apple.
A．the; a
B．a ; the
C．a; a
D．the ; the
压缩机的滑动轴承一般采用（）
A.轴封
B.接触式密封装置
C.不密封装置
D.填料密封
