1. Useful. On the basis that a large amount of salt and sugar in paragraph (3) can act as preservatives, paragraph (4) further explains a problem that is more easily overlooked by consumers. Excessive salt and sugar are more harmful, as well as soy sauce and pickles. It is even more noteworthy to claim that they contain no preservatives. (only from the perspective of "further". )

2. It cannot be deleted. In other words, the second half sentence "about 80% of which is water, sugar, essence, pigment, thickener and other auxiliary materials" is the author's reasonable inference, so that readers can see the truth behind the rhetoric of food packaging. And delete, indicating that the second half of the sentence should also be written on the packaging, which is not in line with the purpose of such businesses.

3.( 1) Subtext: This product is a good choice for middle-aged and elderly people, diabetics and obese people. This is an "upscale" and "nourishing" product.

? (2) Truth: Some non-sucrose ingredients make people's blood sugar rise faster than sucrose. Not containing sucrose does not mean that the nutritional components are higher than other products. It may contain other sugars, such as starch, dextrin, syrup and grease. (That's right)

4.A