8、“may as well not…as”结构，此结构可译为“与其……不如不……”。
One may as well not know a thing at all as know it but imperfectly.
9、“have only to …do”结构，此结构表示“只须(消)……就能……”的意思。
We have only to turn to that extraordinary discovery made by Edison to see the significance of it.
10、“not (no) …unless…”句型
No increase in output can be expected unless a new assembly line is installed.
