Water that contains a larger than normal amount of is still safe to drink.
a. sulfur b. arsenic c. lead d. magnesium

Water that contains a larger than normal amount of magnesium is still safe to drink.

Explanation:

Sulfur, lead and arsenic are harmful metals that are toxic to human health. Although magnesium present at high concentrations (above  approximately 250 mg/l each) can have a laxative effect. However, data suggest that  consumers adapt to these levels as exposures continue.

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.

the inner core.

good luck: )

klicker