Take the following as truth: If he had spent time in the archives, says van Pelt, he would have found evidence about ventilation systems, ways to introduce Zyclon B into these buildings--but of course I don't think he knows German so it wouldn't have helped very much.
Then the following statement: "He was researching on the chemical reaction of Zyclon A into the walls of the building.  " is true, false, or inconclusive?