A. la comida frita es la asada(roasted) para la salud(health).
b. carlos tiene 10 años y alejandro tiene 17 años. carlos es alejandro.
c. la leche es la soda para la salud(health).
d. la jirafa es la gallina.
e. la serpiente es el pollito.
f. el pescado es el pollo para la salud.
g. la cebra es el caballo.
h. sofia tiene 6 años y marisol tiene 9 años. marisol es sofia.

1. más alta que
2. tan alta como
3. menor que
4. mayor que
5. mejor que
6. peor que
7. tan saludable(healthy) como
8. más larga que

Firstly note that in Spanish as well as in English there are comparative adjectives, which may be classified as follows:

1. Comparative of superiority

2. Comparative  of inferiority

3. Comparative of equality

But in practice, there are two basic rules to write a sentence with comparatives:

Comparatives of superiority and inferiority:

Comparative of equality :

Knowing this, let's begin with the answers, taking into account the following sentences are a good example of the usage of this comparatives:

In this sentence we are comparing fried food with roasted food taking into account its effects on health, resulting the fried food worse than roasted food.

In Spanish the comparative adjective worse than is peor que, and in this case we have to use the first rule explained above:

Subject + verb + comparative adjective + que + object

Therefore the complete sentence is:

Fried food is worse than roasted food for health

In this sentence we are comparing the ages of two persons, Carlos and Alejandro; resulting Carlos younger than Alejandro.

In Spanish the comparative adjective younger than is menor que, and in this case we have to use the first rule.

Therefore the complete sentence is:

Carlos is 10 years old and Alejandro is 17 years old.  Carlos is younger than Alejandro.

In this sentence we are comparing the effects on health of two types of beverages: milk and soda; resulting the milk better than soda.

In Spanish the comparative adjective better than is mejor que, and in this case we have to use the first rule.

Therefore the complete sentence is:

Milk is better than soda for health

In this sentence we are comparing the height of two animals: the giraffe and the hen; resulting the giraffe taller than the hen.

In Spanish the comparative adjective taller than is más alta que, and in this case we have to use the first rule.

Therefore the complete sentence is:

The giraffe is taller than the hen.

In this sentence we are comparing the length of two animals: the snake and the chick; resulting the snake longer than the chick.

In Spanish the comparative adjective longer than is más largo que, and in this case we have to use the first rule.

Therefore the complete sentence is:

The snake is longer than the chick.

Note that here we used larga instead of largo, because la serpiente is a feminine noun.

In this sentence we are comparing how healthy are two types of food, resulting that both are equally healthy (saludable).

In this case we have to use the second rule explained above:

Subject + verb + tan + comparative adjective of equality + como + object

Therefore the complete sentence is:

Fish is as healthy as chicken for health.

In this sentence we are comparing the height of two animals: the zebra and the horse; resulting that both are equally taller.

So, in this case we have to use the second rule related to the comparative of equality. Therefore the complete sentence is:

The zebra is as tall as the horse

In this sentence we are comparing the age of two girls: Sofía and Marisol; resulting Marisol older than Sofía.

In Spanish the comparative adjective older than is mayor que, and in this case we have to use the first rule.

Therefore the complete sentence is:

Sofia is 6 years old and Marisol is 9 years old. Marisol is older than Sofia.

probably orange juice since in a restaurant they give you a drink first.