I hope they accept this in the future: 有两个水瓶在桌子上
Its specific to water bottle, but people use it a lot
If there was a “在” available I'd do "有两个瓶子在桌子上“ which would be correct, right? I used the word bank so I put down "有两个瓶子桌子上" which was marked incorrect.
Your 1st sentence is correct, but the 2nd one isn't. It is fair to mark it incorrect.
Why is 上 sometimes sererated from the object it relates to and put at the end of the sentence and sometimes right next to the object it relates to?
Can you give an example of the end-of-sentence usage?