The invisible rays of the()beyond the violet end are called the ultraviolet rays. A: speculation B: spectrum C: sleet D: range
The invisible rays of the()beyond the violet end are called the ultraviolet rays. A: speculation B: spectrum C: sleet D: range
In the secondary structure of roots, xylem rays and phloem rays belong to ( ). A: Secondary rays B: Vascular rays C: Pith rays
In the secondary structure of roots, xylem rays and phloem rays belong to ( ). A: Secondary rays B: Vascular rays C: Pith rays
以下属于直接电离辐射的是（） A: X-rays B: γ-rays C: β-rays D: neutrons
以下属于直接电离辐射的是（） A: X-rays B: γ-rays C: β-rays D: neutrons
Children should have glasses which_____ out UV rays.
Children should have glasses which_____ out UV rays.
There has been developed a method for producing vastly more powerful rays.
There has been developed a method for producing vastly more powerful rays.
The anti-UV mutation of microorganisms must be induced by ultraviolet rays
The anti-UV mutation of microorganisms must be induced by ultraviolet rays
X-rays used to measure the progress of a disease are called ______ rays. A: repeated B: serial
X-rays used to measure the progress of a disease are called ______ rays. A: repeated B: serial
Ultraviolet rays from the Sun can cause which of the following?
Ultraviolet rays from the Sun can cause which of the following?
X-rays and gamma rays can be used to detect and treat cancer ______.
X-rays and gamma rays can be used to detect and treat cancer ______.
The seven rays of the Statue of Liberty’s crown symbolize the seven continents of the world.
The seven rays of the Statue of Liberty’s crown symbolize the seven continents of the world.