Thank you Rabbi Kornfeld for your prompt response on why we may say louder than the Chazan "Amen Yehei Shmei Rabah".

And now question on Berachos 48b, Torah & Bris in Birkas Ha-aretz. The Gemara states that Torah and Bris Milah must be mentioned in Birkas Ha-aretz. Rashi gives the reason because the land was given on conditions of Torah and Bris Milah and he quotes two psukim. If indeed Torah and Bris are essential and integral part of Birkas Ha-aretz then why are they left out of Birkas Mei-ein Shalosh ? Rav Shlomo Mendel gave a shiur beiyun yesterday in Boropark on a related topic, He said that the Shita Mekubetez asked the question but doesn't answer it. He offered his answer which I find difficult, but maybe you can explain it or offer another answer. Rabbi Mendel answered that Birkas Mei-en Shalos is not an abbreviated version of the full Birkas Hamazon, as explained by the Brisker Rav, but rather an abbreviated version of the brachot found in Birkas Hamazon. Therefore, Birkas Mei-ien Shalos mentions at the end Shabos, Yom Tom and Rosh Chodesh, because these three items were formulated into a Bracha format at the end of Birkat Hamazon if they were missed in their proper place during benshing( end of Daf 49a.). Using that logic, Rav Mendel continues, since no Bracha was formulated to replace Torah and Bris Milah if missed in Birkas Ha-atetz, therefore they don't belong in Birkas Mei-in Shalosh. Rav Mendel added that this logic also explains why Chanuka and Purim are not mentioned in Birkas Mei-ein Shalosh. I asked Rav Mendel that Torah and Bris Milah are not comparable to Shabos or Yom Tov or Rosh Chodesh. These three items are not integral part of benshing but occasional additions for which a new bracha can be formulated if missed. But Torah and Bris are integral part of Birkas Ha-aretz, as explained in Rashi above, and are not subject to a replacement if missed , just the same way that Ha-aretz itself cannot be replaced by another Bracha if missed, and yet Ha-aretz is found in Birkas Mei-ein Shalos. Rav Mendel answered that The Brisker Rav writes that obviously Torah and Bris Milah are not integral parts of Birkas Ha-aretz.I don't understand that last comment, in view of the fact that our Gemara says several times that Torah and Bris are essential in Birk as-Ha-aretz and, therefore , if missed, the entire Benshing must be repeated. Please enlight me. Thank you.