他在大学里教授寄生虫学，专注于寄生虫与宿主之间的相互作用。

He teaches ___parasitology at the university, focusing on the interactions between parasites and their hosts.

她在大学里专攻寄生虫学，研究如何控制寄生虫传播。

She specializes in ___parasitology at university, studying how to control parasite transmission.