Can someone me? i think it might be (d) but i'm not i need the answer as soon as possible!

which best explains why a washing machine represents an open system?

(a) it has multiple cycles, such as wash or spin

(b) most washers can use a variety of laundry detergent brands

(c) the amount of wash in a load varies

(d) water and power come from external sources

graph question answered .. you think better when you are relaxed and happy

pecialized keyboards

this is an example of "committed" time.

committed time, as contracted time, takes need over essential and available time since it is seen as profitable work. it alludes to the time allotted to keep up a home and family. at the point when a man is commuting using committed time this individual may feel that the drive is an obligation to family, for example, strolling youngsters to class or driving a mate to work. contracted and committed time clients may feel that their commute could really compare to the commute of important or leisure time clients on the grounds that their commute is profitable work. in this manner, they might be more disposed to pick a mechanized method of movement.  

3. dark matter

empty space could also be a simple vacuum