I’m thinking it would be c sorry if it’s wrong .
Answer A the more traing the more you will know
Explanation:
The answer is number 2) Increase the resistance of the concrete to freeze-thaw damage.
Answer:
The Canon EOS 250 is a digital DSLR that features a 24MP sensor. It is powered by the Canon LP-E17, which is a rechargeable Lithium-Ion battery pack.
Explanation:
I say the answers is A but if you mean ventilation in the area of the room then answer B