It′s said that aliens tried to warn the astronauts

stay away离开,远离的意思.
这句话的意思是 据说外星人试图警告月球上的航天员离开,可能他们不喜欢人类靠近他们.那其他的两个选项是什么意思，可以在说一下用法么，谢谢stay out 呆在户外；不回家；持续到...结束That was the first time Elliot stayed out all night.那是埃利奥特第一次彻夜未归。stay behind （1）依旧落在(…)后面(别人离开后)留下来不走，留在后面：She deliberately stayed behind after work to go with me.下班后她故意留下来等我一起走。（2）留在…后面，保持与…的距离：It's safe to stay well behind the car in front to avoid runing into it.离前面的车保持一段距离是安全的，以防追尾事故。