下列哪一项是孕激素的生理作用

A．增强子宫收缩力，增强子宫平滑肌对催产素的敏感性

B．使宫颈口闭合、黏液减少，变稠，拉丝度减少

C．使 * * 上皮增生和角化

D．使乳腺管增生， * * 、乳晕着色

E．加强输卵管节律性收缩的振幅

It is required by the authorities of school that students should be treated ______ by their teachers but how can a teacher respect them when the students show no respect for him?     [ ]

A. in respect  

B. with respect  

C. for respect  

D. by respect