With words like Fruit and Vegetable, do we put "s" after them?

For example, if I want to get people to guess a riddle by writing:

It feels heavy.
It looks like ( a kind of fruit or fruit or fruits????????)
It tastes juicy.

Guess a kind of (fruit or fruits?????)

If I want people to guess other riddles by giving clues such as:

Guess a kind of (dessert or desserts????)
(Vegetable or vegetables????)

Thanks for helping, teachers! ^o^
a kind of fruit

various kinds of fruits

the sentence should be in parallel.

We don't use s on some words that don't have plural form. But once we do, that means two different types of them.

She is running a restaurant serving wine and food(s). Americans won't accept that an s being used on ' food '. But it seems that people like to use an s to mean various food instead.

Another example : peoples

it means different types of peopleEmotion: smile
Students: We have free audio pronunciation exercises.
"It looks like an apple."
"It looks like a strawberry."

"Guess what kind of dessert I've got here." or
"Guess what dessert I've got here."
Many thanks to both teacher whl626 and buggah for helping again! ^o^
English lover rather Emotion: stick out tongue. Not a teacher, so you'd better double confirm with some good teachers hah Emotion: stick out tongue
Students: Are you brave enough to let our tutors analyse your pronunciation?