零件图尺寸标注基本要求中的“正确”是指（）。

A、标注的尺寸既能保证设计要求，又便于加工和测量

B、须符合制图标准的规定，标注的形式、符号、写法正确

C、布局要清晰，做到书写规范、排列整齐、方便看图

D、即尺寸标注须做到定形尺寸、定位尺寸齐全

―How come I didn’t get the message that we were to have the meeting at 4 pm?

―Well, your phone ________ it．

A．might have missed

B．can’t have missed

C．should have missed

D．needn’t have missed