Before revision:  Another important feature of the new extended system is that it can easily handle problems that require specialized quadrature for weakly singular kernels  . Numerical results illustrate the improved performance of the fast direct solver for the new extended system when compared to the fast direct solver for the original extended system.
After revision:  Another important feature of the new extended system is that it can easily handle problems that require specialized quadrature for weakly singular kernels can be easily handled . Numerical results illustrate the improved performance of the fast direct solver for the new extended system when compared to the fast direct solver for the original extended system.