短信预约提醒成功
frontier n.边界，边境，边疆，指靠近边界(boundary)的区域;也可引申为"未开发的领域"，"(学术的)前沿"等。
The American West was still a frontier a century ago.一个世纪以前美国西部还是一片边疆。
She is a biochemist who works on the frontiers of biology.她是从事生物学前沿研究的生化学家。
verge n. (道路、花坛等长着草的)边缘，引申为"某事即将发生之际"。
On the verge of war，she was on the verge of a nervous breakdown.战争爆发之际，她几近精神崩溃。
11、conserve，preserve都有“保护，保存”的意思
conserve v.保存，保藏，保护(强调节约)。
In winter， some people conserve energy by lowing the heat at night.冬天，有些人在夜里通过调小暖气来节约能源。
preserve v.保护;维持;保养;防止(食物)腐败(强调使不受破坏)。
The government preserves the rights of the individual person.政府保护个人的权利不受侵犯。
12、convert，invert，revert，transform同形或同意
convert v.转变，皈依，含有"使某人改变观点"的意思。(联系converse)
He wants to convert to Catholicism.他要皈依天主教。
invert v.使颠倒，使倒转，使反向。常常表示位置、顺序、方向等的颠倒。(联系inverse)
The baby inverted the cup and spilled her orange juice.婴儿把杯子打翻，弄洒了橙汁。
revert v.归还，恢复原状。指回到原来的状态或情形。(联系reverse)
John gave his brother a house， and when his brother died， ownership reverted back to John.约翰送给他的哥哥一所房子，当他的哥哥去世后，房子的所有权重新归于约翰。
transform v.改变，转变，指形状、颜色、大小、性质等的改变。
A little paint will soon transform the old house.刷一点油漆很快就会使这所旧房子大为改观。
13、credible，credulous，plausible，同形或同意
credible a.可信的，可靠的。
That the student told the teacher a credible story that she missed classes because she was sick.那个学生跟老师讲了实情，她因为病了才没来上课。
credulous a.轻信的，易于相信的。
She was credulous when she listened to the salesman and bought the car for too much money.她很容易轻信别人，竟然听信那个销售员的话以高价买了那辆车。
plausible a.似乎有理的(可信的)。常带有怀疑的意思。
Even though it is a plausible explanation， I am not completely convinced.虽然这个解释似乎合理，但仍不可能使我完全相信。