"To preform specific useful computing tasks, like word processing and calculation" is the correct answer. This is the whole purpose of system software. The third answer is some other type of software(third party software?) and the fourth answer is most likely a compiler. Those are the easiest to take off. The second could also work.
The two answers I would go with are the first and the second.
Alt and tab to switch to open applications
For applying the filter you need to select the data on which you want to apply it so it will allow you to look at only data you select from the filter options.
I would say drawing a polygon for a new model, assuming that the polygon would be converted to 3D to create the model.
(I really hope this helps)
More than one sound source and listening device<span>
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