【词组解析】
1. invisible to 不可见的
（1）Many stars overhead are invisible to the naked eye.
天上的许多星星是肉眼看不到的。
（2）Bacteria are invisible to the naked eye.
细菌是肉眼看不见的。
2. jealous of 嫉妒
（1）An honorable Chinese citizen should be jealous of his own rights.
一名光荣的中国公民应当珍惜自己的。
（2）I'm very jealous of your new job.
我很羡慕你的这个新工作。
3. just now 眼下;刚才
（1）You were rude to say that to your father just now.
你刚才对你父亲讲那种话太不礼貌了。
（2） Please wait a minute, he is engaged just now.
请稍等一会儿，他正有事呢。
4. keep one's eyes on 关注
（1）I always keep my eyes on the ball and forget everything else.
我总是盯住那个球而忘了所有其他的事情。
（2）In the meantime, keep your eyes on the night sky!
同时，把你的眼球锁定在这个夜空！
5. keep on 爱好；反复地做；不停地；继续进行
（1）Will you keep on the course of exercises until you are thinner?
你要继续这项训练直到身体瘦下来为止吗？
（2）I won't keep on waiting more than half a minute.
我不会再继续多等一分钟。