呼吸暂停是指()
A.呼吸停止15秒以上
B.呼吸停止20秒以上
C.心率<100次/分,无发绀
D.心率<100次/分伴发绀
E.心率>100次/分,无发绀
参考答案:B, D
企业如何做好标准化工作?
We all thought()pity that you were unable to attend our meeting.
A.that
B.which
C.this
D.it