能降低往复泵流量脉动率的常用方法是（）。
A．设吸入空气室
B．设排出空气室
C．降低转速
D．设飞轮使转速更均匀
参考答案：B
With the word “ PM2.5” _________ appearing in media reports, people pay greater attention to it and seek health tips for smoggy days.
A．constantly
B．consequently
C．permanently
D．immediately
肿块位于肾与肾上腺区时，可判断为肾脏肿瘤的MRI表现是()
A.肿瘤大部分位于肾上腺区
B.肾皮髓质分界消失
C.肾皮髓质分界清晰可见
D.肾上腺显示不清
E.肿瘤与肾脏分界清楚
