诊断瞳神紧小的主要依据是：
A．抱轮红赤B．黄仁纹理不清C．黑睛后壁有灰白色物附着，伴神水混浊D．目珠坠痛E．视物模糊
参考答案：C
以下主要用于管网分流或合流或旁通处的各支路风量调节的风阀是( )。
A．平行式多叶调节阀
B．复式多叶调节阀
C．对开式多叶调节阀
D．三通调节阀
20.______ that caused him to serve dinner an hour later than usual.
A．It was we being late
B．It was our being late
C．It was we were too late
D．It was because we were late
