When doing medical research and human subjects which four limitations are unavoidable

How does the release of trapped gases in magma cause a volcano to erupt? a. they push the magma up the pipe and then are reabsorbed into the magma chamber. b. they cause the magma to change chemically into lava. c. the gases form vents that allow the magma to flow out. d. the gases rush out and carry the magma with them.

Suppose you are estimating the size of a blue crab population. what is the population size if the number marked in the first catch is 40, the total number in the second catch is 200, and the number marked in the second catch is 50?

Getting out of bed is the first goal i tackle each day. 2several small goals are achieved by me as the day progresses. 3when i am riding the bus home or walking the dog, i think about the bigger goals i have for my life. which statement correctly describes the verb tense, aspect, and voice in this paragraph? a.sentences 1 and 2 contain present progressive verbs. sentence 3 contains both present progressive and simple present verbs. sentence 2 uses passive voice. b.sentences 1 and 2 contain simple present verbs. sentence 3 contains present progressive verbs. all three sentences use active voice. c.sentences 1 and 2 contain present progressive verbs. sentence 3 contains simple present verbs. all three sentences use active voice. d.sentences 1 and 2 contain simple present verbs. sentence 3 contains both present progressive and simple present verbs. sentence 2 uses passive voice.