属于滞流流动状态的雷诺数是()。
A、Re=8000
B、Re=5000
C、Re=30000
D、Re=2000
参考答案:D
It was the most boring report we had ever had. It ___ four hours.
A.ended
B.finished
C.was
D.lasted
日本学者古川竹二的血型说认为A型气质的特点是( )。
A.温和
B.老实、稳妥
C.多疑
D.不愿吃亏