Questions 30 to 32 are based on the passage you’ve just heard.

A．It has different color.
B．It has air inside.
C．Sediment gets stirred up and mixes with water.
D．It’s not mentioned in the conversation.

A．She finds her handbag missing.
B．She forgets where she put the keys;
C．She can’t find her keys.
D．She left her keys in the office.