force: is the general term and implies the overcoming of resistance by the exertion of strength, power, weight, stress, or duress: ~d the prisoner to sign the confession.      duress强迫胁迫to force or threaten sb to do sth


compel: typically requires a personal or personalized object and suggests the working of authority or of an irresistible force: all workers are ~led to pay taxes.


coerce: suggests the overcoming of resistance or unwillingness by actual or threatened severe violence or intimidation: ~d by gangsters into selling his business.    intimidate恐吓表示让人恐惧或自卑


constrain: suggests a forcing by constricting, confining, or binding action or choice: ~ed by my conscience to see that justice was done.       constrain有两个意思 1、限制to limit, restrict，如research has been constrained by a lack of funds
研究工作因经费不足而受限制 2、强迫不得不to force，如the evidence was so compelling that he felt constrained to accept it证据是那样的令人信服，他觉得不得不接受


oblige: implies the constaint of necessity, law, reason, or duty: I am ~d to inform you of your rights.   名词obligation义务，本例: 我有义务告知你你的权利


force强制: 泛指强力逼迫(文中用克服抵抗overcome resistance)，compel逼迫: 用权威权力强制人，宾语是人不是物，coerce胁迫: 通过暴力恐吓，constrain受约束: 由于约束限制如良知而不得不，oblige有义务: 由于法律、责任或道理


记忆方法: 1) 首字母OF CCC属于3C认证<==强制   3C是中国强制性产品认证China Compulsory Certification的缩写。问: 3C中的compulsory是哪个词的派生词，用法是否正确? 答: 是compel的派生词，用法正确，只有compel强调“权威权力”

        2) 强制的意思是使屈服mean to make someone or something yield.首字母OF CCC属于3C认证<==强制