Answer: question 1 would be on the computer as he is not inside it.
question 2 would be on as the time is on top of the watch.
question 9 would be behind as trailed means to drag behind.
question 14 would be at the gate.
question 16 would be on the beach as the waste is on top of the beach.
question 17 would be at the table as the children are not sitting on top of the table.
Explanation:
The grammatical name is Conjunctional Clause and the subject housewife supplements the conjunction a/an
Means someone or something is very light weight, metaphor