enter on/upon

(formal)begin (an activity or job); start to pursue (a particular course in life)

(正式)著手（活動，工作）；開始（生活道路）

he entered upon a turbulent political career.

他開始了動蕩不定的政治生涯。

(Law)(as a legal entitlement) go freely into (property) as or as if the owner

(律)（作為法律賦予的權利）正式占有

enter into

To participate in; take an active role or interest in

加入：參加；在其中扮演一個積極的角色或對其有興趣

enter into politics; enter into negotiations.

從政；參加談判

To become party to (a contract)

締結：成為（一項條約）的訂立方

The nations entered into a new agreement.

這些國家簽署了一項新的協議

To become a component of; form a part of

使納入：是…的一部分；構成…的一部分

Financial matters entered into the discussion.

財政問題納入討論之列

To consider; investigate

考慮；審議

The report entered into the effect of high interest rates on the market.

這報告討論的是市場高利率的影響

enter on 或 enter upon

To set out on; begin

著手；開始

We enter on a new era in our history. They entered upon the most dangerous part of the journey.

我們進入了歷史上的新紀元。他們開始了旅行中最危險的階段

To begin considering; take up

開始考慮；著手做

After discussing the budget deficit, they entered on the problem of raising taxes.

討論過預算赤字之后，他們開始考慮增稅問題了

To take possession of

占有，獲得

She entered upon the estate of her uncle.

她獲得了她叔父的不動產