Proportional method and bisectional method were introduced to optimize the dosage of every surfactant.

用比例法与对分法优化各表面活性剂用量；

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Councillors in Scotland are usually elected to multi-member wards under proportional representation using the "single transferable vote" method.

BBC: Labour wins South Lanarkshire Council majority

Just to add complication, each will have a different electoral system: council elections in May will be by the traditional first-past-the-post method, European elections in June by a proportional system.

ECONOMIST: Devolution