a. 各半的, 利弊各半的, 对半的
ad. 各半, 利弊各半地, 对半
英汉词典

fifty-fifty的短语、例句：

fifty-fifty adj, adv (infml 口) shared or sharing equally between two 对半（的）; 二一添作五
divide the profits on a fifty-fifty basis, ie take equal shares 平分利润
a fifty-fifty chance of winning, ie an equal chance of winning or losing 胜负的可能性参半
We went fifty-fifty on dinner, ie shared the cost equally. 我们平摊用餐费.