1. biologists in darwin's time had already begun to understand that living things change over time. how did darwin contribute to these ideas?
a. he found many fossils that showed that these changes could not possibly happen on islands
b. he figured out and explained how these changes happened and supported his ideas with evidence
c. he made guesses about how these changes happened, and wrote experiments that could be used to test these guesses
d. he was the first person to truly believe that these changes happened, and he worked very hard to convince others

b. He figured out and explained how these changes happened and supported his ideas with evidence

Explanation:

Darwin, through his studies as a naturalist on the voyage of HMS Beagle was able to figure out how evolution occur and explained the changes that happened with several supportive evidence.

During the exploration, Darwin participated in several studies including anatomical, morphological, and paleontologist studies after which he published his books on 'The origin of life'.

In the book, Darwin explained how organism evolve with time and he was able to support his hypotheses with multiple evidence. He later formed the theory of natural selection based on his studies.

The correct option is b.

the answer is b: 1.4 km/hr

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.