Every minute he could spare was made use ____ spoken English.

A．of practising

B．of to practise

C．to practise

D．to practicing

测定人体的BMR应在下列哪些条件下进行( )

A．进食12h后

B．清醒、静卧半小时以上

C．避免精神紧张

D．室温在20～25℃范围内

E．以上都不是