In other words, invisible rays had passed through the cardboard.
换句话说, 就是一道不可见光穿透纸板投射到外面来了。
2016 English Cafe
This is a machine that uses invisible rays called " x-rays" that go through the human body in order to see what's inside the body.
这是一种机器,它使用称为“X 射线”的不可见射线穿过人体,以查看体内情况。
Step by Step 3000 第二册
The observatory changed the astronomers' views of the heavens, after showing that the entire universe is bathed in the invisible gamma rays, but highest energy form of light.
天文台改变了天文学家对天空的看法,表明整个宇宙都沐浴在不可见的伽马射线中,但能量最高的光形式。
夏日走过山间
Perhaps the invisible rays that struck me while I sat at work on the Dome are something like those which attract and repel people at first sight, concerning which so much nonsense has been written.