instruction:
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.
question:
Fact 1: Most species go through larval stages after hatching. 
Fact 2: Glowworms are the larvae of some species.
answer:
glowworms hatch.


question:
Fact 1: Secondary growth forms secondary vascular tissues and bark. 
Fact 2: Trees have the ability to undergo secondary growth and produce a woody body.
answer:
trees form secondary vascular tissues and bark.


question:
Fact 1: a speedometer is used for giving a driver feedback on the speed of their vehicle. 
Fact 2: Trucks and cars are vehicles.
answer:

a speedometer is used for giving a driver feedback on the speed of their truck.