大中城市交通特点有哪些？
参考答案：
人多车杂，子巷密布，交通拥挤。交通管理组织与设施比较严密、完善，行人有遵守交通规则的常识和良好的习惯。
―Which would you like, a hamburger or a sandwich?
― _____ of them is OK. I think _______ of them are delicious.
A．Either, All
B．Neither, both
C．All, either
D．Either, Both
攻一M10mm X l.2mm的螺纹，求钻孔的钻头直径为多少mm。
