I think the easiest language to learn would be Chinese. I'm not so sure about Khmer, but Korean alphabet might be rather tedious to learn for beginners, as compared to the Japanese alphabet. There are slight differences between Chinese and Japanese characters, but Chinese is bye far the easiest language to learn when compared to Japanese and Korean as it's grammar is the simplest to grasp.

No matter where they are or under any circumstance, all living things need water. 应该是这样说的吧

Satisfactory: 使你满意的东西或事件，比如服务态度或者一个人给你的回应或答复。通常用来形容达到你的标准的东西（比如服务态度），但不能用来形容卓越的服务。 比如： -The service was satisfactory. Satisfying: 满足个人的，或某种需要，满足欲望，比如食欲。 -The meal/food is satisfying