The part of the sentence "cannot be changed once" is correct and usable in written English.
You can use it when you want to emphasize that something is not reversible once it has been set or done. For example, "The terms and conditions of this contract cannot be changed once they have been agreed upon."
This selection cannot be changed once your request is submitted.
But any technology aboard a satellite cannot be changed once it is launched.
In fact, for a number of them, including Cheaptickets.com and 1Travel.com, domestic tickets are nonrefundable, and the flights cannot be changed once the ticket is bought.
Please note that course units are particularly important since they cannot be changed once a given quarter opens for enrollment (October 28, 2018, for Winter Quarter; February 10 , 2019 for Spring Quarter).
Abundances of course cannot be changed once defined and the accumulated emissivities are computed and in fact, the atomic number for this "fake line" must be set to 1 to avoid introducing spurious normalization errors.
Can they guide their robot through an obstacle course using a list of simple directional instructions that cannot be changed once the robot has set off? Explore programming further with upper primary pupils by using this activity to create a 2D robot made of card.
While aesthetics can easily be changed once you own the home, these factors cannot.
An irrevocable trust cannot be changed by you once it is signed.
Currently, most automatic seizure prediction methods are focused on offline methods, of which models cannot be changed and improved once they are built up [ 7– 16, 20, 21].
Commodities, which can be had free from the government, must be requested as early as March, and those orders, once approved, cannot be changed.
That is to say, there is no technical reason to carry forward the "limitation" that pen and ink imposes on ledger writers, that an entry – once made – cannot be changed without leaving marks on the page that evidence the change.
