In this task, you need to count the occurrences of the given word in the given sentence.

Sentence: 'train cars lined up under a bridge full of traffic'. Count the occurrences of the word 'under' in the given sentence.
1

Sentence: 'a young man is on his board while in the air'. Count the occurrences of the word 'his' in the given sentence.
1

Sentence: 'a room that has three sofa chairs one of which has a painting on it'. Count the occurrences of the word 'a' in the given sentence.

2