A ray of light normally travels in a straight line through empty space, but if the ray passes close by a massive object, the curve in space created by the star acts like a bend in the road, causing the light ray to veer away from its formerly straight path.
并列一：A ray of light normally travels in a straight line through empty space.
并列二：but if…the curve in space acts like a bend in the road
1.if the ray passes close by a massive object条件状语从句
2.created by the star后置定语，修饰curve
4.causing the light ray to veer away from its formerly straight path 状语；
=the curve in space cause...
今天的句子The modern society cannot function properly without trust, a faith that other people or organizations will act fairly and honor their promise.
词汇突破：1.act fairly 公平行动
2.honor their promise 遵守诺言
Dishonor the promise /commitment 违背承诺