假设有一台摄像机，它的扫描速率为450行/帧×520像素/行×25帧/秒，图像子采样

“意外型”通货膨胀是投资者根据以往的数据资料对未来通货膨胀的预计，也是他们对未来投资索求补偿的依据。（）

It's impolite to sit there with your feet __________at others.[ ]

A. pointed                      

B. pointing

C. to point                      

D. to be pointed

先天性十二指肠闭锁有哪些特征()

A．钡灌肠盲端位于右上腹

B．呕吐物含胆汁

C．腹立位平片双泡征

D．上腹可见明显胃蠕动波

E．右上腹可触及橄榄样肿物

既能清肺热、降肺气而化痰止咳，又能清胃热、降胃气而止呕止呃的药物是( )

A．桑白皮
B．柿蒂
C．枇杷叶
D．地骨皮

A negative metacentric height（）.

A.will always cause a vessel to capsize

B.should always be immediately corrected

C.always results from off-center weights

D.All of the above are correct