Translation:I drink water.
I think it's because in Chinese, many verbs require a noun. For example if you want to say "eat" you can't just say 吃， you have to add a noun. Since rice 饭 is the most common food in China, to simply say "eat" is to "eat rice - 吃饭＂。 I am guessing it works the same way with water 水。 To simply say "drink", you need to add the most common beverage which is water.
After the sign "I", I chose the signs 1 by 1 "drink" and "water" instead of using the combined sign "drink water" and the program gave an error message.
Could this also be translated as "I am drinking water" or it'd require another structure?