leap in the dark . step taken in ignorance of the consequence 不管结果如何贸然行事；鲁莽之举；冒险
The experiment was a leap in the dark．此项实验实在是冒险。
I'm about to make my last voyage，a great leap in the dark．我就要作最后的航行，一次大冒险。
It will be a leap in the dark to make an important decision without investigation．不进行任何调查就作出重要的决定将是冒险的行动。
leap into . suddenly enter 突然闯进
A great idea just leaped into my mind．我突然想到一个绝妙的主意。
leap out . be noticeable 引人注目
His name leaped out at me from the newspaper．他的名字出现在报上，引起了我的注意。
learn of . come to hear about听说
How did you learn of my name? 你是怎么知道我的名字的?
I learnt of your success in the newspaper．我从报纸上得知你成功的消息。
learn something by heart . learn by memory 默诵；暗记
Everyone in the class has to learn by heart Lincoln's Gettysburg Address．班上每一个学生都必须默诵林肯的盖茨堡演说词。
Leave to . leave up to . give the choice or decision to 让…来决定、选择；把某事交给…处理
Since you don't want to decide，leave the matter up to your boss when he returns．既然你不想作决定，就让你老板回来后作决定吧。
I left the choice of colours for the house up to my wife．我让我妻子来选择房子的颜色。
Now you just leave it to me．这事你交给我好了。
leave alone . not bother or interfere with；not touch 不要打扰；不要碰
Go way and leave me alone．走开，不要管我。
You leave my sister alone or I'll be telling my father．别惹我妹妹，不然我要告诉我爸爸了。
Leave that machine alone．别碰那台机器。
leave alone . cause somebody to remain alone 撇下…一个人；让…一个单独呆着
I don't want to be left alone．我不愿一个人呆着。
leave behind . go away without 遗留；留下
Can you tell me the time? I've left my watch behind．你能告诉我时间吗? 我把手表掉了。
I realized I'd left my umbrella behind on the train．我意识到把雨伞忘在火车上了。
leave for . go to；start for 离此而去…；往…出发…
We are leaving for Canada next week．下星期我们要去加拿大。
leave off . stop 停止
Please leave off biting your nails．请不要咬指甲。
He told the boys to leave off teasing his little brother．他要那些孩子们停止戏弄他的小弟弟。
I think we should leave off now and have a cup of tea．我想我们该停下来喝杯茶了。
We leave off work at twelve．我们十二点钟下班。
leave off . no longer wear；stop wearing or using不再穿；不再使用
They left their woollen underwear off when the weather got warm．天气转暖时，他们不穿羊毛衫了。
She left her coat off when she went out．她没穿外衣就出去了。
I have left off my overcoat．我已经不穿大衣了。
He has left off all other medicines．他已停服其它所有的药。
leave on . continue wearing继续穿
I feel a bit cold so I'll leave my coat on．我觉得有点冷，所以外套就不脱了。
It is rude for a man to leave his hat on indoors．一个男子在室内仍戴着帽子是不礼貌的。
leave on . allow to stay in place or position 使…留在原处
Leave the cloth on．I want to lay the table for supper．台布不要取下，我要摆桌子开晚饭了。
leave on . not switch off 不关
The electric fire had been left on overnight．电炉整夜没有关。
Don't leave the light on when you go out? 出去时，请关灯。
I want to leave the soup on all morning to thicken it ．我想把这个汤煮一个上午，让汤煮稠点。
leave out . omit 省略；删去
We can leave out the third sentence．我们可以删去第三句。
You can leave out the details；just give us the main facts．你可以省去细节，就告诉我们主要的事实就行了。
leave out . neglect to put in 遗漏
In copying this paper，be careful not to leave out any word．抄这个文件时，不要漏掉任何一个字。
She left out an important detail in her account．她的账目漏掉了一个重要的项目。
leave out . exclude；ignore 排除；忽略；冷落（某人）
Please leave me out of your plans．你的计划中请不要把我考虑在内。
Don't leave our teachers out from the invitations．请不要忘记邀请我们的老师们。
It is Mary's own fault if she feels left out at the party；she makes no effort to be friendly to people．要是玛丽感到在晚会上遭冷落，那是她自己的过错，她一点也不想亲近人们。
You left out the possibility that the train might be late．你忽略了火车晚点的可能性。
leave out . leave available 留下备用
If you aren't home when I go to bed，I'll leave some food out for you．如果我睡觉时你还没回来，我就给你留饭。
leave somebody to himself . leave somebody to look after himself；not control somebody 听任某人自行其是；自己照看自己；不去管
I decided to leave Jim to himself after he had refused to accept any of my suggestions．吉姆拒绝我的任何建议之后，我决定一切由他去。
The children were left very much to themselves during the holidays．孩子们在假期中可以自由活动。