702年武则天在为加强对北天山的管辖，设立了什么机构？（）
参考答案：北庭都护府
He bought a book that could glee him much knowledge and ______ could help him to kill the time．
A．that
B．where
C．which
D．there
锅炉应每年进行一次停炉做外部检查；每六年进行一次水压试验。
