What caused Francesco Lana to plan an airship? A.
the measurement of mercury
B.
the invention of balloons
C.
the mixture of different gases
D.
the discovery of air having weight

Which of the following best explains why the author chose the compare-and-contrast structure for paragraph 2

In a series of experiments, hershey and chase radioactively labeled dna and protein in viruses and then used labeled viruses to infect bacteria. hershey and chase's experiments definitively showed that a. dna and not protein is the genetic material. b. dna and protein work together as a cell's genetic material. c. protein and not dna is the genetic material. d. neither dna nor protein act as a cell's genetic material

What does the birdcage symbolize in trifles?