What vs. which

[nara]

English Grammar Tests, Elementary Level

ESL/EFL Test #93 "Why Questions", question 2

......... is measured by the Richter Scale?

(a) What
(b) Which
(c) Where
(d) Who

English Grammar Tests, Elementary Level

ESL/EFL Test #93 "Why Questions", answer 2

What is measured by the Richter Scale?

Correct answer: (a) What
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why what?

[Conchita]

'What' is the correct option here, because the question is about what thing among an unlimited number of possibilities. 'Which' refers to what thing from a small or limited number of answers.

[Daemon99]

1) What book are those lines from?
2) Which book are those lines from?

Can someone please tell me which of the above sentences sounds natural? When do I use what and when which?
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Non-native speaker of English
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I intend to live forever - so far, so good.

[Kitosdad]

Good afternoon Daemon. I believe that the first is the correct form to use.

1) What book are those lines from?

Which would be used when there are only a couple of items to choose between. What is used where a limitless number of items are in question.
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Keep it simple ... Keep it interesting.

[Nodirbek]

Hi
What is the meaning of word "measured"?

[Sunil36]

what class do you study in? or which class do you study in? & what company do you work in? Or which company do you work in? please tell me which one is correct

[Beeesneees]

Use 'which' when there are a set number of classes/companies to choose between. (For example, when you are asking about classes in a particular establishment or about companies in a particular field).

Use 'what' where a limitless number of classes/companies are in question.
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Cheers m' dears!