No he did not that was a poor choice.
Answer:
200 nm
Explanation:
We need a constructive interference to see the bright reflection
we know that 
where m=1 and 
is the wavelength of the gasoline
so 
putting the value of m and in thickness equation
so the thickness of the film will be 200 nm
Answer:
The correct answer is C. Sometimes.
Explanation:
A database index is a structure that aims to speed up selections and selective operations on a database. An index reduces the number of comparisons required to find one or more database records. This avoids having to perform a so-called full table scan, whereby all records in the table have to be run through sequentially.
Therefore, if the search does not focus correctly on the necessary data, this search will not always determine the index of the goal. Therefore, the user must correctly handle the search keywords to collaborate with the system.
