其它
What is the value of  $\frac{1}{2}$~$\cdot$~$\frac{4}{2}$~$\cdot$~$\frac{3}{5}$ $\ldots$~$\frac{18}{20}$~$\cdot$~$\frac{19}{21}$~$\cdot$ $\frac{20}{22}$ 
Overseas Competition->Knowledge Point->Calculation Modules
NA 