Which is the closest antonym for the word spontaneous?

Press enter to interact with the item, and press tab button or down arrow until reaching the Submit button once the item is selectedApredetermined

Bdistinguished

Cexaggerated

Dunfavorable

The closest one I found was casual

It's B

Explanation:

Which of these had not yet happened when this article was written?

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A. Scientists found out which bacterium was responsible for the plague.

B. Doctors developed antibiotics to treat the disease caused by Y. pestis.

C. Researchers found different versions of the bacterium Y. pestis.

D. People got the bubonic plague after coming into contact with rats.

(i clicked B the first time and got it wrong, this is for Achieve3000 btw)