银原子的直径为0.0003微米,相当于( )米(用科学记数法表示,1微米=10﹣6米).
3×10﹣10
— What did Jack ask you just now?
— He wanted to know how long _____ when I reached the cinema. [ ]
A. had the film been on
B. the film had started
C. the film had lasted
D. had the film ended
一般用于存放供其他Access数据库对象使用的公共过程称为______。