Select the number line that shows that two opposite numbers have a sum of
0.

D

Step-by-step explanation:

When you have two opposite numbers on a numberline, that is, a digit that has a negative value and the same digit having a positive value, when you add them together, we would have 0.

i.e. -a + b = 0

In the above options given, the numberline that shows this particular case is the numberline in option D.

In option D numberline, the sum of -1 and +1 equals zero.

d. millimeters per hour.

step-by-step explanation:

we are given that,

carlo used a rain gauge to measure the amount of water his lawn is receiving from the sprinklers.

since, according to the options, we see that,

water cannot be measured by 'miles per hour', 'meters per second' and 'grams per seconds'.

we get that, the water can be measured by 'millimeters per hour'.

hence, the appropriate rate for describing the amount of water is 'millimeters per hour'.