1)enable,允许;生效2)allowable equivalent grain size,允许等效粒径3)the coverage allowed by ecology,生态允许覆盖度4)assent,允许;允许书5)allow,允许，准许6)permit,允许，许可
用法例句
By analyzing and comparing several concepts about vegetation coverage given by other specialists,several new threshold of vegetation coverage are put forward:the coverage allowed by ecology,the coverage demanded by ecology and the coverage allowed by economy,then the methods are given to calculate.
