Read the following passage and choose the best answer to fill in each blank.

My uncle is working at a car company. His company is now developing (21) ________ new flying car. The  car will have solar panels on its roof and wings, and it will charge (22) ________ battery as it moves. During  light traffic, you can use roads. (23) ________ in heavy traffic, you can use the flight mode to avoid traffic. It  will be able to carry eight passengers. The car will have an autopilot function, so a driver is not (24) ________.  All passengers can relax, read books or play games while travelling.

 I was worried (25) ________the safety because it is driverless, but my uncle said it will be much safer than a  traditional car. It will also be more comfortable and greener because it is solar-powered.

His company is now developing (21) ________ new flying car.