--Will you please give me some ideas on __________ English at home? 

--Well, do a lot of reading and listen to English programs.

A．how to read

B．how to learn

C．when to use

D．where to use

测速管流量计的测量原理是，装在管道中心的一根带有小孔的金属管，末端对着流体流向，以侧流体的动压力。