4. Among the following four arithmetic expressions, the one with the largest result is expression $\qquad$.
(1) $992 \times 999+999$
(2) $993 \times 998+998$
(3) $994 \times 997+997$
(4) $995 \times 996+996$
【Analysis】(4)
(1) $992 \times 999+999=(992+1) \times 999=993 \times 999$
(2) $993 \times 998+998=(993+1) \times 998=994 \times 998$
(3) $994 \times 997+997=(994+1) \times 997=995 \times 997$
(4) $995 \times 996+996=(995+1) \times 996=996 \times 996$

Since the sum of two numbers is constant, the smaller the difference, the larger the product; therefore, the result of the expression with number (4) is the largest.