Boil the water to get remove the salt and then use filter paper to remove the microorganisms
Answer;
A plain
Explanation;
A contour line connects points of the same elevation. Contour lines are usually curves. Closed contours represent hills.
Contour lines can not cross since they represent different elevations. A contour interval is the difference in elevation between one contour and an adjacent contour.
If we neglect friction/air resistance, then the horizontal component
doesn't change, and the vertical component becomes (9.8 m/s downward)
greater each second thanks to gravity.
So, after 2 seconds, the horizontal component is still 40 m/s, and the
vertical component is (30 - 2·9.8) = 10.4 m/s upward.
Choice #1 says this.