In the following passage, there are blanks, each of which has been numbered. These numbers are printed below the passage and against each, five words are suggested, one of which fits the blank appropriately. Find out the appropriate word in each case.

 Growth in agricultural output over the past three decades has been strong and, importantly, crop production has been able to (31) keep pace with the demands from a growing population. The introduction of high-yielding seeds such as improved (32) of wheat from the mid 1960s and the increased use of chemical fertilizers (33) what became known as the 'green revolution'. Wheat production (34) by nearly 150 percent between the mid 1960s and mid 1970s and the country became self-sufficient in grain (35) by the end of the 1970s. The increase in agricultural production (36) rural incomes while also causing food prices to fall. This had the effect of reducing rural poverty (World Bank 2004). Despite the productivity (37) in the Indian agricultural sector over recent decades,yields remain low by international standards and growth in yields has only been (38) higher than the world average. In particular, yields for cereals and vegetables remain (39) lower than the world average. Crop yields have increased much more for rice and wheat than for other cereals, such as barley, or for pulses. Wheat yields have tripled over the past 50 years and rice yields have doubled, while yields for pulses Improved (40) over this period.