Read the texts below and complete each space with ONEsuitable word. Global warming may be threatening one of the world’s most important crops: rice. Increased nighttime temperatures are associated with significant declines in crop (46) , according to a study conducted by researchers at the International Rice Institute. The researchers analyzed twelve years of rice production along with twenty-five years of temperature data. This study, a direct measurement of yields produced under normal field conditions, using (47) that good farmers normally employ, has confirmed previous simulations and suggests that (48) increases due to global warming will make it increasingly difficult to feed the Earth’s growing population. Average (49) temperatures, which increased 0.35 degrees Celsius over the (50) of the study, have little effect on rice production. However, a strong correlation exists between warmer nighttime temperatures, which have risen an average of 1.1 degrees, (51) decreasing rice yields. Although the underlying (52) of this relationship is unknown, researchers speculate that plants work harder to maintain themselves in (53) to the warmer nights and consequently divert energy from growth. Thus, an average (54) of just one degree Celsius can (55) in a ten percent reduction in yields. Similar findings have been reported for corn and soybean yields in the United States.