1 . 听下面一段独白，回答小题。
1. How can frozen food be kept cold at ordinary temperatures?

A．By using bags.

B．By using water.

C．By using paper.

2. What is advised to do when camping?

A．Use special dry foods.

B．Never cook meat or eggs.

C．Keep milk in a cooler box.

3. What is the passage mainly about?

A．How to pick up fresh food.

B．How to eat healthily in different weather.

C．How to keep food from going bad in summer.