Which would result a farmer in producing more food at a lower cost? planting wheat that is resistant to weed killer breading pear trees that grow sweeter fruits growing rice that only grows in warm climates producing vegetable oil that has added vitamin a

The answer is: 'planting wheat that is resistant to weed killer '. The question is, 'which would result a farmer in producing more food at a lower cost'. Therefore, the answers should indicate a larger mass of food produced at a lower cost. Two of the other options don't increase the mass of food produced, they only change the characteristics of the crop: sweeter pears and vegetable oil with vitamin A. The remaining option would not increase the mass of crop produced as the rice would not grow in cold climates. Only the option indicated above would increase the mass of crop, as wheat would not be affected by weed killer whereas the weeds will be removed. The use of weed killer would reduce the amount of wheat lost, thereby reducing the cost.   

The open ocean begins at the low-tide mark and extends to the end of the continental shelf

above statement is not a true statement about the open ocean because the open ocean has low levels of nutrients. most of the photosynthetic activity on earth occurs in the open ocean within the photic zone. organisms in the deep ocean are exposed to frigid temperatures and total darkness but it does not begin at the low-tide mark.