The Sun and other stars are powered by nuclear fusion reactions, in which two atoms collide to form a single heavier atom, releasing energy. Scientists have long believed that fusion has the potential to meet humanity’s clean energy needs. ______blank prior to December 2022, no fusion reaction in a laboratory setting had ever generated a net energy gain.
","stem_html":"Which choice completes the text with the most logical transition?
","rationale_html":"Choice D is the best answer. Scientists believe in fusion’s potential as an energy source, but have struggled to actually make it work—in other words, there is a contradiction between scientists’ beliefs and their reality. “That said” is a disagreement transition that works perfectly in this context.
Choice A is incorrect. This choice uses a cause-and-effect transition, which doesn’t make sense here. Scientists not being able to generate extra energy from lab fusion reactions isn’t an effect of them believing in fusion’s potential. Choice B is incorrect. This transition indicates the addition of another supporting point. But this sentence is not adding a supporting point to the previous sentence—scientists not being able to successfully generate energy from fusion isn’t another point in favor of fusion meeting humanity’s clean energy needs. Choice C is incorrect. This choice uses a transition that introduces or elaborates on a particular example. But this sentence doesn’t give an example of scientists’ belief in fusion’s potential to meet humanity’s clean energy needs—in fact, it contrasts that optimistic belief with the reality of past failures to successfully employ fusion for energy production.
","correct_answer":["D"],"has_media":false,"has_mathml":false,"has_table":false,"source_created_at":"2023-08-02T20:25:59.373000+00:00","source_updated_at":"2023-08-02T20:25:59.373000+00:00","options":[{"label":"A","content_html":"For this reason,
","ord":0},{"label":"B","content_html":"Moreover,
","ord":1},{"label":"C","content_html":"Specifically,
","ord":2},{"label":"D","content_html":"That said,
","ord":3}],"attribution":{"source_id":"cb_question_bank","source_name":"College Board digital SAT question bank (community dump)","rights_holder":"College Board","canonical_url":"https://satsuitequestionbank.collegeboard.org/","retrieved_from":"https://raw.githubusercontent.com/mdn522/sat-question-bank/main/data/cb-digital-questions.json","attribution":"SAT practice questions © College Board, from the official SAT Suite Question Bank. Retrieved via the community dump at github.com/mdn522/sat-question-bank.","disclaimer":"SAT® and PSAT/NMSQT® are trademarks registered by the College Board, which is not affiliated with, does not sponsor, and does not endorse this project.","license":"College Board copyright; source repository carries no licence. Local use only.","redistributable":false,"item_count":2017}}