1. SAMPLE vs. this proposal:
 A) Though the slope on C2u/C2d plane is close, they are nevertheless different
    linear combinations;
 B) Sample has theoretical uncertainties due to anapole corrections, thus an 
    independent measurement as proposed here is important;
 C) The factor of 8 improvement is from a comparison of the expected result and 
    previous data on 2C2u-C2d (SLAC), not from comparison to the SAMPLE result. 
    In the proposal, always mean "compared to previous data on THIS COMBINATION 
    (refering to 2C2u-C2d)".

2. Q2=1.1 vs 1.9 GeV^2:
 A) HT has Q2-dependence, always necessary to have two points;
 B) Low-Q2 measurement suffers more from systematics. For example, from Tabel 4 
    (page 26), the systematic uncertainty is Delta (2C2u-C2d)_syst=0.0243 for 
    Q2=1.1 and 0.0158 for 1.9 GeV^2, respectively.  Therefore if we want to 
    measure 2C2u-C2d to 0.03 at Q2=1.1 GeV^2, we will need much smaller statistical 
    error, which requires 42 days of beam time.