问题
选择题
Children, either in the city or in the country, should have ______ to the equal education. [ ]
A. chance
B. choice
C. access
D. approach
答案
答案：C
搜题请搜索小程序“爱下问搜题”
Children, either in the city or in the country, should have ______ to the equal education. [ ]
A. chance
B. choice
C. access
D. approach
答案：C
，P到O的距离为L，如图所示。不计重力的影响。求磁场的磁感应强度B的大小及xy平面上磁场区域的半径R。 
