On|On Writing Well C15 OnWritingWellC15

1.words and expressions bent

If you’re a student with a bent for science or technology, don’t assume that the English department has a monopoly on “literature."

名词[usually sing.]
~ (for sth) a natural skill or interest in sth
(某方面的)天赋,爱好:
She has a bent for mathematics.
她有数学天赋。
flunk

I once flunked a chemistry course taught by a woman who had become a legend with three generations of students, the legend being she could teach chemistry to anybody.

动词在(考试)中不及格; 未通过(某一课程)；If you flunk an exam or a course, you fail to reach the required standard. [V n] [Mainly AM] [Informal]
Your son is upset because he flunked ahistory exam.
你儿子心烦意乱是因为没有通过历史考试。
flunk 是美国口语，注意下面各句：

He flunked. （他考试不及格。）
He flunked the examination. （他考试不及格。）
His teacher flunked him. （他的教师使他不及格。）
He had a flunk in his entrance examination.
nail sth. down

Slowly the two men piece together fragments of evidence that seem to defy medical history until the case is nailed down and the villain identified as a type of poisoning so rare that many standard texts on toxicology don’t even mention it.

1.文中意思[PHRASAL VERB 短语动词] 弄清; 确定；If you nail down something unknown or uncertain, you find out exactly what it is. [V P n (not pron)] [Also V n P]

It would be useful if you could nail down the source of this tension.
如果你能弄清这种紧张的根源，将会大有益处。
2[PHRASAL VERB 短语动词] 确定(协议)；If you nail down an agreement, you manage to reach a firm agreement with a definite result. [V P n (not pron)] [Also V n P]
The Secretary of State and his Russian counterpart met to try to nail down the elusive accord.
美国国务卿和俄罗斯外交部长进行了会晤，试图敲定这项难以达成的协议。
3[PHRASAL VERB 短语动词] 钉牢; 钉住；If you nail something down, you fix it firmly onto something. [V n P] [Also V P n (not pron)]
Lay strips of 4mm ply over the mesh and nail these down with panel pins.
把4毫米厚的胶合板条铺在网子上，然后用镶板钉钉牢。
2.summary 【On|On Writing Well C15】