1. si no entiendes algo, vas a sacar una buena nota.
2. no debes prestar atención en las clases.
3. hay que aprender de memoria las palabras nuevas.
4. el equipo de ajedrez es un club atlético de la escuela.
5. los músicos tienen que ensayar para tocar bien.

c. encontramos

explanation:

if i am wrong i am sorry : )

b.

explanation:

just because.

well, the b sentence is the only one that has sense.

ancient india is often called the harappan civilization because one of the ancient cities was called harappa. harappa was just one of 1500 cities in the indus river valley. another well-known city is called mohenjo-daro. historians estimate ancient india to be the biggest of all four early civilizations.