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Hello.
Is the article needed in these sentences? Does it depend on the context?

May I leave (the) class early?
French movies are better than (the) English ones.
Scientists need to study (the) life below the surface of the ocean.
It's difficult to choose between (the) career and (the) family.
He has bumps from (the) head to (the) foot.

Nobody had (a) pity on him.
This sunscreen provides (a) long-lasting protection against UVB rays.
I am (a) drug addict.
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May I leave (the) class early?
"Leave class" sounds like "stop learning in class" and "leave the class" sounds like "go out from the class room". I'll choose "leave class" in this context.

French movies are better than (the) English ones.
No doubt "English movies (in general)" (without THE).

Scientists need to study (the) life below the surface of the ocean.
I'll go with "life" without THE. Because I take "life" here is used in a generic sense.

It's difficult to choose between (the) career and (the) family.
"Between career and family" is an idiomatic phrase.

He has bumps from (the) head to (the) foot.
"From head to foot" is also an idiomatic phrase.

Nobody had (a) pity on him.
"Have pity on".

This sunscreen provides (a) long-lasting protection against UVB rays.
"Protection" is uncountable.

I am (a) drug addict.
"A drug addict".

paco
Comments  
LatinHello.
Is the article needed in these sentences? Does it depend on the context?

May I leave (the) class early?

Either one, but I'd advise using the article in British English.

In BrEng, "leave the class" does not normally mean "leave the classroom" - as suggested by Paco. It means "leave before the class has ended".


French movies are better than (the) English ones.

For generalising, no article: for particularising, an article is useful. E.G.

French movies are better than the English ones we've been getting on TV lately.