下述类型设备中，承压性能最好的是（）。
A.球形容器
B.圆筒形容器
C.方形容器
D.椭圆形容器
参考答案：A
定常流动.
She changed so much that I could hardly _____ her when we met again after a separation of 10 years.
[ ]
A. recognize
B. know
C. remember
D. tell
