Do you think that a biotic or a abiotic factor can be both positive and negative in the same environment? Explain.

No, biotic and abiotic factors are the environmental conditions that the organisms have to face to live in a specified environment. Abiotic factors are the physical and chemical conditions of an environment. For example : heat, salinity, pressure, light, wind, pH.Biotic factors are all the biological conditions of an environment for a specie/taxa. It can include prey and predator abundance, available food amount, available space, intra and interspecific competition... The development of organims is under the control of abiotic factors. Some are adapted to heat, cold etc ... The abiotic factors will define which organisms are able or not to live in a specified place. The living organisms will constitute the biotic factors, which define if and how can an organism live in a specified environment. So, the abiotic factors are controling the biotic factors of an environment.

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

hope this

i think the answer would be a. after sentence 14! i hope i at least a little