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.

Example Input: Fact 1: Gametes then unite in fertilization and form a diploid zygote. 
Fact 2: Zygotes are diploid and undergo cell division to become an embryo.
Example Output: Gametes then unite in fertilization and eventually become an embryo.

Example Input: Fact 1: Cells cannot survive without oxygen. 
Fact 2: Survival is to live, to live means hope.
Example Output: Cells cannot live without oxygen.

Example Input: Fact 1: Echinoderms use pheromones to communicate with each other. 
Fact 2: All echinoderms are deuterostomes .
Example Output:
at least some deuterostomes use pheromones to communicate with each other.