Answer:
C
Explanation:
The helix has to unwind before separating. Once it's separated, then new bases can be added. Once the bases are added, the separate strands wind into helices.
Answer:
The tympanic membrane and stapes of the bullfrog can be driven by airborne sound over a wide frequency range, with a broad maximum in their velocity amplitudes between 0.4 and 2 kHz (Mason and Narins, 2002a).
Mouth, pharynx, esophagus
B. sulfur tetrafluoride + water → hydrogen fluoride + sulfur dioxide