管道送煤气结束前要在其末端,取样进行爆发试验,不然炉子点火会产生爆炸。（）
参考答案：错
—Mary looks down today. What is up?
—Well，________happened between Mary and me is none of your business.
A．wherever
B．whoever
C．whatever
D．no matter what
了解子宫内膜同期变化的主要方法是
A．诊断性刮宫
B．基础体温
C．雌激素试验
D．宫颈黏液检查
E． * * 脱落细胞检查
