矿井在剩余可采储量比为（）%左右，且无进一步扩大储量的可能时，即进入收尾阶段。
A.10
B.20
C.30
D.40
参考答案：B
I can hardly believe my eyes. What a poor composition you have _______. There are so many wrong spellings in it.
A．turned into
B．turned off
C．turned to
D．turned in
抗中性粒细胞胞浆抗体对哪种疾病的诊断有帮助
A．类风湿关节炎B．干燥综合征C．皮肌炎D．系统性硬化病E．血管炎
