18. How has the use of herbicides affected agricultural productivity? O A. Fewer crops are organic because of the use of Bt toxin.
B. Fewer pesticides are needed because of parasitoids.
O C. Fewer people are needed to weed because of herbicides.
D. Fewer crops are produced because of herbicides.

B. Fewer pesticides are needed because of parasitoids.

Explanation:

Herbicides are chemicals utilized to manage or command unwanted vegetation. Herbicide employment happens most commonly in row-crop cultivation, where they are employed before or throughout seeding to maximize yield productivity by decreasing other vegetation.  Yields have improved considerably, and, in association with tillage, herbicide use decreases erosion, fuel usage, greenhouse gas discharges, and nutrient run-off, and preserves water.

the transfer for conduction is the heat transfering from the liquid to the spoon

the transfer for convection is the heat rising from the liquid to the air

the transfer for radiation is the heat going through the sides of the cup and to the air

at least that is what i would do

acceleration= v2-v1/t so 8m/s-3m/s / 3s =to 8/3 or

2.67 m/s^2

hope i

-lavira: )