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: Condoms can break; Condoms can be used incorrectly. 
Fact 2: If the condom breaks, withdraw the penis and condom immediately.

SOLUTION: a broken condom should be discarded immediately.

PROBLEM: Fact 1: Some viruses can cause cancer. 
Fact 2: Some cancers are fatal.

SOLUTION:
some viruses can be fatal.