1.hallway vs hall
p187, We have a switch for outside lights, a switch for the hallway lights, a switch for the living room lights, and a switch for the bedroom lights.
hallway和hall的意思差不多，都是指"a passage in a house(走廊)"， 它们之间的一个微小差别是：hallway implies “narrow passage”, hall implies “large space or room”。
2.flinch at
flinch: make a sudden small movement of pain or fear(这是物理意义上的)，也可以用于比喻意义(退缩)。
示例：p213, Languages are simply tools, and learning to use a new tool should not be something a programmer flinches at.
3.negligible
p214, However, in well-made interpreters, this time can be fairly negligible.
(1)negligible: negligence + -ible。
(2)negligence: neglect。
(3) neglect: *ne-(“not”) + *leg-(“to collect, gather”).vt. to not give enough care or attention to sth(忽视)。