—Could you tell me ______?

—Of course, last night.

A．when you reached our town

B．when did you reach our town

C．how you came to our village

D．how did you come to our village

螺纹连结的常用防松措施是增大摩擦力和（）。

A、机械防松、弹簧垫圈

B、机械防松、双螺母

C、止动垫圈、双螺母

D、机械防松、不可拆