Question

as soon as i sat ____ the school bus, I remembered that I had left my lunch box ____ my desk.

Answer 1

As soon as I sat on the school bus, I remembered that I had left my lunch box on my desk.

Explanation:

• The correct preposition for both the blanks is "on".
• The first blank uses "on" to show that the speaker is traveling while he remembered that he had forgotten his lunch box. This blank can be contradicted by using "in" but "in" would simply mean that the speaker is inside the bus and it would not give any idea about the state of the bus.
• The second blank shows that the lunch box of the speaker was on the desk. This blank can also be contradicted by using "at" but again "at" would just give the idea of the place where the lunch box can be found it will not state whether it is "under" or "on" the desk.