This sentences might be complete in the following way:
"el tomate está al lado del vaso de jugo" This would mean that the tomato is next to the glass- In the case of "encima de", it would mean that it is on the glass. "debajo de" would mean under the class. And if we say "entre", that would mean that we need another object to put the tomato in the middle because it meas "between".
