Which number comes next in the pattern 121, 109, 99, 91, __

85

From 121 to 109, it subtracted 12.

From 109 to 99, it subtracted 10.

From 99 to 91, it subtracted 8.

As you can see, the pattern is subtracting two less than the time before.

So for the next number you would do: 91-6= 85

85 is the correct answer, sorry I have to type 20 characters

d) -1

step-by-step explanation:

water molecules will move from the side of higher water concentration to the side of lower concentration until both solutions are isotonic. at this point, equilibrium is reached. in an isotonic solution, the flow of water in and out of the cell is happening at the same rate.

hope this < 3