It's a nice day, _ ? [ ]
A. is it
B. isn't it
C. are they
D. aren't they
答案：B
与子宫内膜增生过长关系密切的是：
A．宫内节育器B．绝育术C．卵巢子宫内膜样癌D．颗粒细胞瘤E．口服短效避孕药
简述《小型制冷装置压力容器定期检验专项要求》的适用范围。
