Answer:
The answer is "Option A".
Explanation:
Series:

Solving the above series:

So, the series is: 
Answer:
GMAW
Explanation:
It's literally the initials of that type of welding
Answer:
d. 90%
Explanation:
As we know that internal combustion engine produce lot's of toxic gases to reduce these toxic gases in the environment a device is used and this device is know as current modeling converter.
Generally the efficiency of current model catalytic converter is more than 90%.But the minimum efficiency this converter is 90%.
So option d is correct.
d. 90%