脾脓肿的超声表现为()
A.脾轻至中度增大
B.脾轻至中度缩小
C.脾内出现无回声区
D.无回声内可见团状,带状回声
E.周边有较强回声带环绕
参考答案:A, C, D, E
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.instantly
C.roughly
D.firmly
天然气的()是指压力每变化1MPa,气体体积的变化率。
A、体积系数
B、弹性压缩系数
C、粘度
D、相对密度