Answer:
Technology is the use of reliable knowledge for a practical purpose.
Ecology is the study of the natural world through observation and experimentation.
Explanation:
The second one
only bases turn litmus paper blue
The formula for aluminum fluoride is 
That means that there is 1 Aluminum and 3 fluorde ions in 1 molecule. The 3 does not effect the Aluminum at all.
The Answer is A
The solution for this problem is:
Let x = speed of wind
Speed of plane with the wind = x + 100
Speed of plane against the wind = 100 -x
We will be using the formula for distance which is (Rate)(Time), getting the formula for time would be distance/rate Time to travel 600 miles with the wind = Time to travel 400 miles against the wind 600/(x + 100) = 400/(100 - x)
400(x + 100) = 600(100 - x)
400x + 40000 = 60000 - 600x
1000x = 20000
x = 20000/1000
x = 20 mph
