1 . 听下面一段独白，回答以下小题。
1. What’s the talk mainly about?

A．The development of the bicycle.

B．The materials of making the bicycle.

C．The process of the bicycle’s becoming popular.

2. What is the disadvantage of the bicycle before MacMillan’s design?

A．The bicycle couldn’t change directions.

B．The wheels of the bicycle weren’t well fixed.

C．The rider’s feet couldn’t leave the ground.

3. When was the size of the bicycle’s wheels changed?

A．In 1817.

B．In 1839.

C．In 1869.

4. What happened in 1884?

A．Bicycles first had rubber tires.

B．The “safety bicycle” appeared.

C．Bicycles could run faster.