【多选题】管内强迫对流流动进口段内的流动状态是:
A.
流动边界层边缘尚未汇合,边界层外流速基本均匀。
【简答题】如图,已知∠ ACD = 70 ° ,∠ ACB = 60 ° ,∠ ABC = 50 ° . 试说明: AB ∥ CD.
【单选题】已知,如图,AB ∥ CD,∠A=70°,∠B=40°,则∠ACD=( )
【单选题】已知:如图,AB ∥ CD,CE平分∠ACD,∠A=100°,则∠ECD的度等于( )
【单选题】Many American schools offer online programs,and international students______.
A.
should be careful of being cheated
B.
are certain to earn a degree
C.
should know about programming
D.
are faced with many difficulties
【单选题】已知:如图AB∥CD,CE平分∠ACD,∠A=110°,则∠ECD等于
【单选题】如图已知:△ABC≌△ACD,AB=AC,BE=CD,∠B=50°,∠AEC=120°,则∠DAC的度数为( )