Which is correct about convection currents? A. Is results to formation of valleys and hills
B. It happen in all layers of the Earth
C. It causes Earthquakes
D. It is made possible by heat and pressure

The illustration shown is an ovum, a female sex cell. a mutation in this cell may be passed to the woman’s offspring during a) birth. b) mitosis. c) dna replication. d) sexual reproduction

Refer to this portion of a dichotomous key for fish identification to answer the question. 1. (a) has a single dorsal fin ® 5 (b) has a double dorsal fin ® 2 2. (a) one fin is spiny, the other is smooth ® 3 (b) one fin is not spiny or smooth ® 4 5. (a) has small fin on back near tail ® 6 (b) has no fin on back near tail ® 7 6. (a) has barbs near the mouth ® catfish (b) does not have barbs near the mouth ® 10 7. (a) tail is asymmetrical ® 8 (b) tail is symmetrical ® 9 10. (a) scales are small ® trout (b) scales are large ® whitefish what is the next step to complete to identify a fish that has a single dorsal fin, no fin on the back near the tail, and no barbs near the mouth? step 2 step 5 step 7 step 10

How far down have geologists drilled holes ? (science) a: 3.8 km b: 12 km c: 100 m d: 1200 km