The substance can be added to gasoline to accelerate the speed of automobiles.（　）

A:quicken B:shorten C:loosen D:enlarge

The substance can be added to gasoline to {{U}}accelerate{{/U}} the speed of automobiles.

A:quicken B:shorten C:loosen D:enlarge

The substance can be added to gasoline to accelerate the speed of automobiles.

A:quicken B:shorten C:loosen D:enlarge

The substance can be added to gasoline to accelerate the speed of automobiles.

A:quicken B:shorten C:loosen D:enlarge

The substance can be added to gasoline to {{U}}accelerate{{/U}} the speed of automobiles.

A:quicken B:shorten C:loosen D:enlarge

The substance can be added to gasoline to {{U}}accelerate{{/U}} the speed of automobiles.

A:quicken B:shorten C:loosen D:enlarge