account for是對?負有責任，說明（原因、理由等），導致，引起，在數量、比例上占的意思。
1、PHRASAL VERB?（數量或比例上）占?
If a particular thing?accounts for?a part or proportion of something, that part or proportion consists of that thing, or is used or produced by it.
Computers account for 5% of the country's commercial electricity consumption.
計算機占去該國商業用電的5%。
2、PHRASAL VERB?導致；解釋?
If something?accounts for?a particular fact or situation, it causes or explains it.
Now, the gene they discovered today doesn't account for all those cases.
不過，他們現在發現的基因無法解釋所有的病例。
3、PHRASAL VERB?為?提出理由;對?作出說明?
If you can?account for?something, you can explain it or give the necessary information about it.
How do you account for the company's alarmingly high staff turnover?...
妳怎麽解釋這家公司高得令人憂慮的人員流動率？
4、PHRASAL VERB?對（行動、政策等）負有責任?
If someone has to?account for?an action or policy, they are responsible for it, and may be required to explain it to other people or be punished if it fails.
The President and the President alone must account for his government's reforms.
總統必須為他的政府改革負責，而且是負全責。
5、PHRASAL VERB?將（錢款）列入預算?
If a sum of money?is accounted for?in a budget, it has been included in that budget for a particular purpose.
The really heavy redundancy costs have been accounted for.
非常龐大的裁員開支已被列入預算。
6、PHRASAL VERB?殺死；消滅；打敗?
If you?account for?an enemy or opponent, you kill, destroy, or beat them.
In the first ten days of May our squadron accounted for at least seven enemy aircraft...
5月的頭10天裏我們中隊至少報銷了7架敵機。