What travels through a food chain/web?

Which type of bond forms between water moleculesstrong bondhydrogen bondcovalent bondpolar bond

The most effective way to provide children with safety messages is to

Ascientist is designing an investigation to study the impact of invasive bird populations on local, native bird populations at backyard bird feeders. what population is most likely to be a control group for the investigation? amount of food number of bird feeders invasive bird populations local backyard birdfeeders without food