instruction:
This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.
question:
Passage: The city shares a 15-mile (24 km) border with Mexico that includes two border crossings. San Diego hosts the busiest international border crossing in the world, in the San Ysidro neighborhood at the San Ysidro Port of Entry. A second, primarily commercial border crossing operates in the Otay Mesa area; it is the largest commercial crossing on the California-Baja California border and handles the third-highest volume of trucks and dollar value of trade among all United States-Mexico land crossings. Question: Where is the next nearest commercial crossing at the border?
answer:
Otay Mesa


question:
Passage: Many more artillery pieces had arrived and been dug into batteries. In June, a third bombardment was followed after two days by a successful attack on the Mamelon, but a follow-up assault on the Malakoff failed with heavy losses. During this time the garrison commander, Admiral Nakhimov fell on 30 June 1855.:378 Raglan having also died on 28 June.:460 In August, the Russians again made an attack towards the base at Balaclava, defended by the French, newly arrived Sardinian and Ottoman troops.:461 The resulting battle of Tchernaya was a defeat for the Russians, who suffered heavy casualties. Question: Who was defeated at the battle of Tchernaya?
answer:
the Russians


question:
Passage: In January 2009, the Green Power Partnership (GPP, sponsored by the EPA) listed Northwestern as one of the top 10 universities in the country in purchasing energy from renewable sources. The university matches 74 million kilowatt hours (kWh) of its annual energy use with Green-e Certified Renewable Energy Certificates (RECs). This green power commitment represents 30 percent of the university's total annual electricity use and places Northwestern in the EPA's Green Power Leadership Club. The 2010 Report by The Sustainable Endowments Institute awarded Northwestern a "B-" on its College Sustainability Report Card. The Initiative for Sustainability and Energy at Northwestern (ISEN), supporting research, teaching and outreach in these themes, was launched in 2008. Question: What grade was given to Northwestern on the 2010 College Sustainability Report Card  by The Sustainable Endowments Institute?
answer:

B-