Answer:
 Y is probably excitatory and Z is probably inhibitory
Explanation:
- Two neurons communicate with each other generally by releasing neurotransmitters.
- The neuron which releases the neurotransmitter is termed as presynaptic neuron and the neuron to which the neurotransmitter binds to exert its effects is called as postsynaptic neuron.
- Based on the nature of the neurotransmitter released, the presynaptic neurons can either be inhibitory or excitatory in nature.
- The change in the membrane potential of the postsynaptic neurons depends on the total sum of inputs coming from different pre synaptic neurons at a given time.
- From the given situation, the stimulation by X alone is causing deploarization of 0.5 mV which shows that it is causing excitation, and since depolarization is increasing when X and Y are stimulaneously stimulated Y is also excitatory in nature. However the depolarisation is not occurring when X and Z are stimualted together and hence, Z is probably inhibitory in nature. 
 
        
             
        
        
        
Answer: Identity moratorium 
Explanation:
Identity moratorium is the third identity status in Marcias theory. This identity represents a high exploration of different things or skill but low commitment to all of them. This is stage of identity crisis in youth. They have tried out different things but are not yet certain of a career type. 
 
        
             
        
        
        
Answer: The greenhouse gas emissions from the extraction of bitumen and the use of large quantities of water.
Explanation:
Bitumen is a natural flammable organic matter formed from kerogen in the process of petroleum generation, which is soluble in carbon disulfide. Asphalt and mineral wax are examples of hydrocarbons which are part of bitumen. Conventional oil is extracted by wells while <u>oil sands deposits are extracted using surface mining sectioning techniques, or are flowed to wells by in situ techniques that reduce bitumen viscosity by steam and/or solvents.</u> So, unlike crude oil extracted in oil wells, bitumen requires an open-pit mining operation, in which large tracts are washed with a mixture of water and chemicals to separate the bitumen from a mixture of sand and clay.
Two consequences of this practice are:
- The greenhouse gas emissions from the extraction of bitumen are larger than the extraction of conventional oil. The emissions produced contribute  to enhance the greenhouse effect and cause global warming. The greenhouse effect occurs when certain gases retain part of the energy emitted by the earth's soil when heated by the sun's radiation. This phenomenon occurs naturally, and thanks to it, the average temperature of the Earth is about 14º C (57.2 °F). The problem occurs when these greenhouse gases increase in the atmosphere and the amount of energy that is not released into space also increases and, with it, the Earth's temperature.
- The extraction of bitumen from oil sands requires the use of large quantities of water, and even though water used here can be recycled, only a small amounts is returned to the natural cycle. Also, spills from the transportation of the oil could damage soils and waterways, increasing water pollution. This toxic water  could get into surface.