Question

however, many years later, a priest returned from traveling around northern africa and he claimed to have met some of the surviving children (who would, at that time have then been adults). he claimed that two of the seven ships had sunk killing all on board and that pirates had captured the other five ships and the children were sold into slavery. white skinned children were considered to be a valuable prize in algerian and egyptian slave markets. there is however, no proof that any of this is true as none of the children who left france was ever heard from or seen again.
→ 8. what is rumored to have happened to the children who went on the crusade?

Explanation:

The problem is about the rumored fate of children who went on the crusades. From the text, a priest claimed some surviving children (who were adults then) said two ships sank (killing all on board), pirates captured five ships and sold the children into slavery (valued in Algerian/Egyptian slave markets), but no proof of this was ever seen/heard again. This relates to historical accounts of the Children's Crusade, where such fates (shipwrecks, slavery) were rumored.

Answer:

It was rumored that two of the seven ships carrying the children sank (killing all on board), pirates captured the other five ships and sold the children into slavery (where white - skinned children were considered valuable prizes in Algerian and Egyptian slave markets), though there was no proof of this being true as none of the children who left France was ever heard from or seen again.