When planning an oral presentation, you want to make sure to do all of the following except practice smiling while presenting. practice holding notes below your waist while presenting. present in front of friends or family. bring a timer to the presentation to keep on time.

Its D. bring a timer to the presentation to keep on time

Explanation:

Presentations don't have to be timed, and usually aren't.

When presenting, you need to talk at a normal speed, otherwise people won't understand what you are saying because your talking so fast.

Not to mention some presentations are long, some are short. It really doesn't matter. Hope this helps!

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.

hey there!

mass = 6.75 g

volume =   9 cm³

therefore:

d = mass / volume

d   = 6.75 / 9

d = 0.7 g/cm³

answer b