Puerto Rico cuenta con una gran cantidad de ríos, lagunas y embalses. Piensa las formas que estos tienen y si se parecen a los que se encuentran
en el continente americano. Debes considerar los factores geográficos y los
climatológicos. Explica.

This is all you, but i can give you some topics that you could try. if it rained when you want to do something outdoors, it 'limits' that human activity. maybe you want to do an experiment that goes throughout the whole year and you have to have above freezing the entire year. this 'limits' your activity. i thought of those just off of the top of my head. something that gets to me that might be getting to you is you are thinking too hard about what to do. think simply, and if it is too simple, then bump it up just a little bit.

Ithink its b but i'm not sure.

Ithink this answer here is a or d

The shia sect of islam is primarily different from sunni islam in the belief that the first legitimate imam following muhammad was imam ali. unlike the three caliphs that succeeded muhammad, ali was part of muhammad's clan (related to him). major shia caliphates include the fatimid and safavid caliphates.  the answer will be option c. shia read more on