Before revision:  We can take this advantage even more, precisely we can achieve a CR } of 2+R{3} if the number of requests in each stage is at most Rk, where R is a constant and 1 \le R \le 2. Both ratios are tight.
After revision:  We can take this advantage even more, precisely we can achieve a CR } of 2+R{3} if the number of requests in each stage is at most Rk, 1 \le R \le 2. Both ratios are tight.