Loess was a problem for the people of the Huang River valley because it A.
caused constant dust storms and eroded good farming soil.
B.
settled on the river bottom, causing the water to rise and flood.
C.
tended to coat young plants, preventing the crops from growing properly.
D.
contaminated the freshwater supply for most of the valley.

It clogged irrigation ditches.

Explanation:

I believe the correct answer is D.

The answer would be b

Explanation:

because the soil settled to the bottom of the River raising water level this destroyed crops and caused mass starvation.

explanation:

aids

8 - (2a + 7) = a + 40     distribute/multiply - into (2a + 7)

8 - 2a - 7 = a + 40

1 - 2a = a + 40       add 2a on both sides

1 = 3a + 40         subtract 40 on both sides

-39 = 3a       divide 3 on both sides

-13 = a

[proof]

8 - (2a + 7) = a + 40

8 - (2(-13) + 7) = -13 + 40

8 - (-26 + 7) = 27

8 - (-19) = 27

8 + 19 = 27

27 = 27