Choose the two sentences from this excerpt that support the claim that more research is needed on both commercial bumblebees and wild species bees.
1. A recent PNAS study published by Sydney Cameron from the University of Illinois Urbana-Champaign traces the collapse of these species to the introduction of commercial bumble bee pollination in the U.S. in the 1990s.
2. It’s possible that after a period of precipitous decline, bumble bee populations may develop a resistance and recover on their own.
3. Or, they could keep declining into oblivion.
4. “All I can tell you is this finding is still correlational,” says Cameron, who is currently seeking funding for a research proposal to compare the immune genes and behavior of infected and