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
The<br/>anti-UV mutation of microorganisms must be induced by ultraviolet<br/>rays.(<br/>)
The<br/>anti-UV mutation of microorganisms must be induced by ultraviolet<br/>rays.(<br/>)
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 ______.