The grain yield per mu B is 985 kg, the cultivated area X is 3.5 mu, the total grain yield s is how many kg? (first use letters to indicate the quantity relationship, then calculate) (1 hectare = 15 mu)

The grain yield per mu B is 985 kg, the cultivated area X is 3.5 mu, the total grain yield s is how many kg? (first use letters to indicate the quantity relationship, then calculate) (1 hectare = 15 mu)

Total grain yield = grain yield per mu × cultivated land area
Letter formula: S = BX
985 × 3.5 = 3447.5kg

Russia has a large area of cultivated land, but it still needs to import a lot of grain. From the perspective of natural conditions, what are the reasons for this phenomenon?

The cold climate is not suitable for crop growth

Why is it wrong to increase grain production by expanding arable land

Because the continuous expansion of arable land will have a great negative impact, such as the reduction of vegetation area, which is not conducive to the sustainable development of the environment