渐渐变为 meaning in English

graduate into
shade into

Acid demineralises the tooth surface which will , hence , be weakened
酸素令牙齿中的矿物质开始分解流失，使牙齿表面渐渐变为脆弱。
But as the conviction gained ground among them that the man in the white hat was doing no harm , and either sat quietly on the slope of the earthwork , or , making way with a shy and courteous smile for the soldiers to pass , walked about the battery under fire as calmly as though he were strolling on a boulevard , their feeling of suspicious ill - will began to give way to a playful and kindly cordiality akin to the feeling soldiers always have for the dogs , cocks , goats , and other animals who share the fortunes of the regiment
但是当大家都相信这个戴白帽子的人不仅不会做什么坏事，而且他或者会安安静静地坐在土堤的斜坡上，或者会带着怯生生的微笑彬彬有礼地给士兵们让路，在炮垒里像在林荫道上似的安闲地在弹雨中散步，这时，对他的敌意的怀疑渐渐变为亲热和调笑的同情，正像士兵们对他们的小狗公鸡山羊，总之，是对生活在军队里的动物的同情一样。