调节阀前后压差较小,要求泄漏景小,一般可选用()阀。
A.单座
B.隔膜
C.偏心旋转
D.蝶
参考答案:A
-How do the students in your school go to school every day?
-Most of them go to school _______the school bus.[ ]
A. by
B. from
C. at
D. on
Chen Dan is kind and is always . [ ]
A. ready to help others
B. ready for help others
C. ready to help the others
D. ready for help the others