GMAT Verbal 36: Reading Comprehension — Mixed Practice

For two centuries Britain's growing appetite for tea depended on a single supplier: China, which guarded both its tea plants and the knowledge of how to process them. In 1848 the East India Company sent the Scottish botanist Robert Fortune into China's interior to change that. Dressed in local clothing and travelling with Chinese guides, Fortune visited tea-growing districts, collected thousands of seeds and young plants, and persuaded experienced tea workers to travel to India.

Moving living plants across oceans had long been nearly impossible; most died on the voyage. Fortune relied on a recent invention, the Wardian case, a sealed glass box in which plants could survive for months in their own moist air. Many of his shipments reached India alive, and with them came the practical knowledge of the workers he had recruited. Among other things, Fortune's travels showed that green and black tea came from the same plant, processed in different ways — a fact that had been widely misunderstood in Britain.

The tea industry of British India, which this transfer helped to build, eventually broke China's dominance of the world tea trade. Fortune's journey is often told as an adventure story, but it was also an act of industrial espionage on behalf of a commercial company, and its consequences for China's economy were lasting.

In the 1940s and 1950s, the American plant scientist Norman Borlaug worked in Mexico to breed wheat that resisted disease. His most important varieties were semi-dwarf: shorter, sturdier plants that could carry heavy heads of grain without falling over. Taller varieties given large amounts of fertiliser grew so heavy that they collapsed before harvest; the semi-dwarfs turned fertiliser into grain instead.

In the mid-1960s, with famine feared in South Asia, India and Pakistan imported large quantities of Borlaug's seed. Combined with irrigation and fertiliser, the new wheat raised yields dramatically, and within a few years both countries were producing far more grain than before. Similar high-yielding rice varieties spread through Asia in the same period. The changes became known as the Green Revolution, and in 1970 Borlaug received the Nobel Peace Prize.

The Green Revolution's critics do not dispute that it produced more food. Their concern is with how it did so. The new varieties delivered their gains only with plenty of water and fertiliser, which favoured farmers who could afford them and placed heavy demands on groundwater and soil. Defenders reply that without the higher yields far more land would have had to be cleared to feed growing populations. Both sides can point to evidence; the argument is now less about whether the Green Revolution worked than about what a second one should look like.