fulfil和fulfill区别是：fil - 践行合约的条款并且达标
e.g. fulfil one's contract / fulfil one's agreement / fulfil the clause of a contract / fulfil one's duty
implement - 具体贯彻、实行计划、方针或某种行动，一般涵盖计划步骤
e.g. implement an action / implement a plan / implement measures
practise - 偏向于形容行业、工业、业界中的某种普行为，用法也较为具体。
tise some industrial acts / practise quality controls on manufacturing / practise installing safety device
carry out - 与implement意思相近，一般不涵盖计划步骤，但是如果形容贯彻计划，可写carry out one's plan。
e.g. carry out an action / carry out a plan / carry out one's duty
