Problem: Gene:

Genes are regulated so that they are expressed only when the product is needed, since expression draws on limited resources.:7 A cell regulates its gene expression depending on its external environment (e.g. available nutrients, temperature and other stresses), its internal environment (e.g. cell division cycle, metabolism, infection status), and its specific role if in a multicellular organism. Gene expression can be regulated at any step: from transcriptional initiation, to RNA processing, to post-translational modification of the protein. The regulation of lactose metabolism genes in E. coli (lac operon) was the first such mechanism to be described in 1961.

What are examples of a cell's internal environment?
---
A: cell division cycle, metabolism, infection status


Problem: 2008 Sichuan earthquake:

Japanese seismologist Yuji Yagi at the University of Tsukuba said that the earthquake occurred in two stages: "The 155-mile Longmenshan Fault tore in two sections, the first one ripping about seven yards, followed by a second one that sheared four yards." His data also showed that the earthquake lasted about two minutes and released 30 times the energy of the Great Hanshin earthquake of 1995 in Japan, which killed over 6,000 people. He pointed out that the shallowness of the epicenter and the density of population greatly increased the severity of the earthquake. Teruyuki Kato, a seismologist at the University of Tokyo, said that the seismic waves of the quake traveled a long distance without losing their power because of the firmness of the terrain in central China. According to reports from Chengdu, the capital of Sichuan province, the earthquake tremors lasted for "about two or three minutes".

Why did the seismic waves travel so far?
---
A: firmness of the terrain


Problem: Qing dynasty:

The Qing dynasty was founded not by Han Chinese, who constitute the majority of the Chinese population, but by a sedentary farming people known as the Jurchen, a Tungusic people who lived around the region now comprising the Chinese provinces of Jilin and Heilongjiang. The Manchus are sometimes mistaken for a nomadic people, which they were not. What was to become the Manchu state was founded by Nurhaci, the chieftain of a minor Jurchen tribe – the Aisin Gioro – in Jianzhou in the early 17th century. Originally a vassal of the Ming emperors, Nurhachi embarked on an intertribal feud in 1582 that escalated into a campaign to unify the nearby tribes. By 1616, he had sufficiently consolidated Jianzhou so as to be able to proclaim himself Khan of the Great Jin in reference to the previous Jurchen dynasty.

What type of lifestyle did the Jurchen live?
---
A: sedentary farming


Problem: Madonna (entertainer):

She met director Guy Ritchie, who would become her second husband, in November 1998 and gave birth to their son Rocco John Ritchie on August 11, 2000 in Los Angeles. Rocco and Madonna suffered complications from the birth due to her experiencing placenta praevia. He was christened at Dornoch Cathedral in Dornoch, Scotland, on December 21, 2000. Madonna married Ritchie the following day at nearby Skibo Castle. Her fifth concert tour, titled Drowned World Tour, started in June 2001. The tour visited cities in the U.S. and Europe and was the highest-grossing concert tour of the year by a solo artist, earning $75 million from 47 sold-out shows. She also released her second greatest-hits collection, titled GHV2, to coincide with the home video release of the tour. GHV2 debuted at number seven on the Billboard 200.

When was Rocco John Ritchie born?
---
A:
August 11, 2000