TASK DEFINITION: Combine the given two facts to write a concluding fact. Note that there should be some parts of the first and second facts that are not mentioned in this conclusion fact. Your combined fact should be the result of a chain between the two facts. Chains form when two facts connect together to produce a concluding fact. An example of a chain is: "pesticides cause pollution" (fact1) + "pollution can harm animals" (fact2) → "pesticides can harm animals" (conclusion fact). Parts of the concluding fact overlap with the first and the second fact. To construct such a  concluding fact, a useful way is to borrow the subject from one fact and the ending conclusions from another fact.
PROBLEM: Fact 1: Insects can spread disease and destroy crops. 
Fact 2: Crops Crops are a farmer's stock in trade.

SOLUTION: insects can destroy a farmer's stock in trade.

PROBLEM: Fact 1: zinc has a positive impact on the healing of wounds. 
Fact 2: Sources of zinc are soil, zinc oxide, zinc sulfate, zinc chelate.

SOLUTION: soil can have a positive impact on the healing of wounds.

PROBLEM: Fact 1: Ethanol is produced by alcoholic fermentation of the glucose in corn or other plants. 
Fact 2: Fermentation is the chemical change of sugar to alcohol.

SOLUTION:
Ethanol is produced from the sugar in other plants changed into alcohol.