10+x=20
Find x
Pls help it is urgent

What is the answer for the complicated molecules that make up living things usually contain carbon. why is carbon so important in these molecules?

Which of the following is not a symptom of desertification? a) decrease in salt content of the soil b) lowering of the water table c) reduced surface water d) increased soil erosion e) loss of native vegetation

Which of the following is not a possible effectof increasimg carbon dioxide levels in the atmosphere ?