【Answer】22
【Analysis】Exam point: Number array $1+2+3+4+\ldots+10=55 ; 55+\mathrm{A}+\mathrm{B}+\mathrm{C}+\mathrm{D}$ can be divisible by 4; then $\mathrm{A}+\mathrm{B}+\mathrm{C}+\mathrm{D}=10$ $+9+8+6=33$; that is $(55+33) \div 4=22$
3. Fill the numbers $1,2,3, \ldots, 9,10$ into 10 circles that form a rectangle, such that the sum of the numbers on each side of the rectangle is equal. The maximum sum is ( ).