The given question might contain grammatical errors, typing mistakes, etc., or might not make sense in the context of the paragraph (for instance, it might not be related to the content of the paragraph or not be answerable at all). In such cases, the question is bad and indicates it by responding "Yes". If you could not find any issue in the given question, respond "No". There are only two types of responses possible:"Yes" and "No".
Q: Paragraph- Sent 1: On a nice and sunny day, Bob and Sally walked to the beach.
Sent  2: When they got there, the first thing they wanted to do was to look for buried treasure.
Sent  3: To find the treasure they had brought two shovels and two buckets.
Sent  4: They both started digging holes in the sand with their shovels.
Sent  5: After looking very hard for treasure for an hour, they didn't find anything.
Sent  6: This made Bob and Sally very sad.
Sent  7: They gave up and went to play in the water.
Sent  8: While they were playing in the water, Sally found a bottle with a little paper inside.
Sent  9: Sally opened the bottle and found a treasure map.
Sent  10: Sally showed the map to Bob and they started to look for the treasure.
Sent  11: After walking every step that the map said, they started digging with their shovels.
Sent  12: After digging a really a big hole, they found a box.
Sent  13: They were very happy that they found it and wanted to see what was inside.
Sent  14: Bob slowly opened the box and there was a very big pearl.
Sent  15: Next, they ran to a special store to ask about the pearl.
Sent  16: The worker in the store told Bob and Sally that the pearl could make them rich.
Sent  17: Bob and Sally looked at each other and decided not to sell it.
Sent  18: They took the pearl home and saved it in a special box, so they could remember their day at the beach.? 
Question: What makes Bob and Sally feel very sad?
A: 
No.