在圆管流中，紊流的断面流速分布符合( )。
A．均匀规律 B．直线变化规律C．抛物线规律 D．对数曲线规律
参考答案：D
Conjunctivitis may be caused by bacteria, viruses, allergens, or irritants. What signs and symptoms differentiate bacterial conjunctivitis from other types
A. Subacute onset, severe pain, and preauricular adenopathy.B. Recurrent onset, no pain, and clear discharge.C. Acute onset, moderate pain, and purulent discharge.D. Acute onset, mild pain, and clear discharg
已知，xn=2，yn=3，则（xy）n=（ ）。
