[填空题]A summary of the physical and chemical nature of life must begin,
not on the Earth, but in the Sun; in fact, at the Sun’s very center. It is here
which is to be found the source of the energy that the Sun constantly pours 41. ______
out into space light and heat. This energy is librated at the center of 42. ______
the Sun as billions upon billions of nuclei of hydrogen atoms collide
with each other and fuse together to form nuclei of helium, and doing 43. ______
so, release out some of the energy that is stored in the nuclei of atoms. 44. ______
The output of light and heat of the Sun requires that some 600 million
tons of hydrogen are converted into helium in the Sun every second. 45. ______
This the Sun has been doing for several thousands of millions of years.
The nuclear energy is released at the Sun’s center as high-energy
gamma radiation, a form of electromagnetic radia