沿儿的英文：
(n) edge, usually used directly after a noun

edge是什么意思：
n. 边，边缘；刀，刀口
v. 使徐徐移动；给...加边

The number of incoming edges is equal to the number of outgoing edges
进入的线数等于离去的线数。

pipe edges sewing machine
滚边缝纫机

Sloth turneth the edge of wit
懒惰会磨去才智的锋芒

usually是什么意思：
adv. 通常，经常；一直，向来

Usually y is a function in math.
X is not a function in math.

Used as the usual style for a baron.
男爵用作男爵的常用称呼。

Mothers are usually gentle with their babies.
母亲对自己的婴儿总是很温柔。

used是什么意思：
adj. 用过的，旧的；习惯于…的

It is used as a reflexive.
它被作为反身代词使用。

That was a balk to us.
那对我们是个挫折。

They help us to be maximal encouraging to us.
他们来帮助我们对我们是个极大的鼓舞。