After the leaves of the plants are injured, the green juice will flow out, and the fragrance of the leaves will become more intense. This "green fragrance" can attract the natural enemies of pests to clear the pests. Researchers use transgenic methods to synthesize the gene of aromatase from green pepper. The Arabidopsis introduced into the Brassicaceae once the larvae of the cabbage butterfly ate the leaf, and the fragrance emitted by the Arabidopsis thaliana will be enhanced, and then the mealworm's natural enemy, the pink butterfly velvet cocoon, swarms the rice in large quantities. The cabbage butterfly larvae can eat the larvae of the cabbage butterfly larva before they form pupae. The researchers, therefore, concluded that if this research result is applied to vegetables, the number of pesticides can be greatly reduced. In order for the researchers' conclusions to be true, which of the following premises must be added. ['The pesticides currently used in vegetable cultivation are mainly used to eliminate pests.', 'The fragrance emitted from the leaves of transgenic vegetables will be enhanced.', 'The "green fragrance" of plants is their weapon of self-defence.', "At present, China's current law allows the cultivation of genetically modified vegetables."]