脉氧仪测定显示SpO2显著下降的情况见于（）
A.重度阻塞性肺气肿
B.休克
C.贫血
D.CO中毒
E.肠源性紫绀
参考答案：A, B, C, D
We are working to raise money for the local homeless shelters. _______ , we are collecting clothing to offer those in need.
A．For one thing
B．Moreover
C．As a result
D．In the end
