In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].

Example Input: (CNN) Your "BPA-free" plastic product may be no safer than the product it replaced, says a new UCLA study that analyzed the impact of a common BPA alternative on zebra fish embryos. The study joins a small but growing group of similar research sounding the alarm about so called "BPA-free" alternatives. "Our findings are frightening and important," said senior author and reproductive endocrinologist Nancy Wayne. "Consider it the aquatic version of the canary in the coal mine." After decades of animal research linked BPA (Bisphenol A), a known endocrine disruptor, to problems with brain and reproductive development, early puberty and a rise in breast and prostate cancer, many manufacturers stopped using the chemical to harden plastics, replacing it with "BPA-free" alternatives. The most common replacement is BPS (Bisphenol S), said Wayne.BPA-free alternatives may be no safer than BPA, say researchersMost common alternative, BPS, linked in study to disruptions of estrogen and thyroid hormones 
 Question:In addition to the effect on estrogen, the study also found both _ and BPS affected the thyroid hormone system.
Example Output: BPA

Example Input: (CNN) In the final months of the 2016 campaign, longtime Donald Trump associate Roger Stone repeatedly discussed his backchannel communications with WikiLeaks founder Julian Assange and claimed knowledge of forthcoming leaks from the group, a CNN KFile review of his public statements shows. Stone's comments about WikiLeaks have come under increased scrutiny as the FBI and congressional committees investigate whether Trump associates were involved in Russian efforts to interfere in the 2016 election. Stone has repeatedly and publicly denied that he had any contact with Russian officials during the campaign. Stone declined to answer questions from CNN for this story. After this story was published, WikiLeaks tweeted, "WikiLeaks & Assange have repeatedly confirmed that they have never communicated with Stone."Stone repeatedly discussed his back channel communications with WikiLeaks founder Julian Assange.Stone has repeatedly and publicly denied that he had any contact with Russian officials during the campaign. 
 Question:Stone tweets -- then deletes -- about communicating with _, writing that he "never denied perfectly legal backchannel to Assange who indeed had the goods on #CrookedHillary."
Example Output: Julian Assange

Example Input: Alexis Sanchez and Eduardo Vargas scored two goals each as Chile beat Peru 4-3 for their second successive victory in the South American 2018 World Cup qualifiers on Tuesday. The victory puts the Copa America winners, who beat Brazil 2-0 last week, level on six points with Uruguay and Ecuador at the top of the 10-nation group standings. Chile took an early lead when a through ball from Mauricio Isla found Sanchez in the box and he slotted past goalkeeper Pedro Gallese. Peru equalised in the 10th minute through Jefferson Farfan. But they were reduced to 10 men in the 23rd minute after Christian Cueva was sent off for a kick at Jorge Valdivia.Arsenal star Alexis Sanchez and Eduardo Vargas scored two goals eachPeru's Christian Cueva sent off after 23 minutes for a kick at Jorge ValdiviaChile's victory means they're top of South American World Cup qualifying 
 Question:A double save by Gallese from Arturo Vidal then Valdivia prevented _ from scoring a fifth after an hour and Paolo Guerrero struck Peru's third in added time.
Example Output:
Chile