As a source of energy on earth, there is nothing like the sun: in a mere one thousandth of one second (.001), the sun emits enough energy to fulfill our planet’s (3)_______ needs for the next 5,000 years.

According to the writer of the passage, people should right now ______

In the future, maybe all cars that run on petrol will be replaced by solar cars, which have been around for a while, but with recent (1)__________ in solar car design and the measurement of photovoltaic cells becoming smaller, the dream of a truly efficient solar car is more reality than fantasy.

The phrase “hide our heads in the sand” in the passage probably means ______.

The word “obsolete” in the first paragraph is closet in meaning to ______.

From the passage, we can infer that ______.

According to paragraph 2, how can the attitude of the future affect the world?

According to the writer, the rate of change in technology______.

A solar car is a vehicle (2)__________ by photovoltaic cells, also called solar cells, which convert sunlight (light energy) into electrical energy.

Which of the following information is TRUE according to the fourth paragraph?

What can be inferred from the last paragraph?

According to paragraph 1, which statement is correct about the current situation for smart cities?

The author described the reduction in number of languages in paragraph 4 as an evidence of ___________.