How does the circulatory and digestive systems work together?
a. the digestive system provides oxygen to circulatory system which then transports it throughout body.
b. the circulatory system brings food to the digestive system to be broken down.
c. the digestive system breaks down food and the circulatory system transports the nutrients throughout the body.
d. these systems do not work together.

Based on the observation that only male crickets produce a song, you hypothesize that a male's song is a form of communication to potential mates. you set up a simple experiment to test this hypothesis. in the laboratory, you place a male snowy tree cricket in enclosure a, which is adjacent to enclosureb. in enclosure b, you place other insects, one at a time, and observe their responses to the male's song. the enclosures are designed so that the two insects being tested cannot see or smell each other, but sound is transmitted from enclosure a to enclosureb.

Which of the following molecules can be broken down into simple sugars? a. nucleic acid b. protein c. lipid d. carbohydrate

Explain why it’s important for scientists to study the sun. list at least two challenges researchers face when examining earth’s nearest star.