these three picture are good example of all three different ads. we have the line art ad which is an artwork type ad that is comprised of a solid black, there are no shades of gray or shades of any other color. the black and white half tone ad (nike) the ad has a combination of dots and an optical illusion of shading. then we have the four color process print ad, where i think the ad is full of color as well as black and white tones.

The art director chose this specific visual to focus on the fact that Heinz is made from real tomatos.

with this ad the art director is getting the cumsumers attention on not only there product being made with recycled products, but also the importance of recycling is beneficial to creating new products.

the focus in this ad is the flame. the art director wants to get the attention of the fire hot flavors of doritos.

The headline for this ad gets lost ineverything around it, it has not significant print style to catch the readers eye, and is quite small conpared to the other heading on the ad.
I  would choose to change the ad by making the statement "Never carry your keys again" as a banner heading arcoss the ad and in bold letters to make that my main statement to catch the readers eye, and get their attention.