$Bài1$
a, 1, $CaC_2+H_2--to--> Ca+ C_2H_2 (k)$
2, $C_2H_2+H_2----> C_2H6 (k)$
3, $C_2H_6+Cl_2---->C_2H_5Cl(k)+HCl$
b,
1, $2CH_4--to--> C_2H_2(k) + 2H_2(k)$
2, $C_2H_2+H_2--to--> C_2H_4(k)$
3, $Br_2+ C_2H_4----> C_2H_4Br_2$
c,
1, $CaC_2+H_2-> Ca+ C_2H_2(k)$
2, $C_2H_2+H_2----> C_2H_4(k)$
VII
1.no, they aren't
2.they first met at the primary school
3.vy likes to joke and play games
4.vy is a pretty girl with dimpled cheeks
5.they usually meet at Mai's room
6.they're in Mai's room
7.this Sunday morning they are going to the school English club
