(G) By/With are both correct, By meaning "next to" as in sit next to me and with giving the same meaning, by might be more informal.
(H) Of
(I) Before(?) Heave means lift a heavy thing with great effot, and it makes no sense for me to say "Lift your book are ___ you start the text" with any of the prepositions available. A book should not be something that requires great effort to lift so no sense in using Heave unless you want to put an unusual word to confuse students, this sentence wording is strange to say the least.
(J) In
(K) About
(L) To
(M) Besides
(N) Up
(O) From
(G) With (H) Of (I) After (J) In (K) About (L) To (M) Besides (N) Up (O) From
Vejo que sua dúvida já foi respondida. Se estiver precisando aprender ingles com aulas focadas em conversação, entre no meu perfil, beleza?