Select the most appropriate option to substitute the underlined segment in the given sentence. Charles Darwin is renowned for his book on evolution, ‘On the Origin of Species’, which laid down a treasure of substantiation that evolution occurs, and projected a mechanism, that is, natural selection, for how it does so.

Correct — C. Lay out means to present or explain something fully and in order, which is what a book does with its evidence.

The underlined laid down is the wrong member of the family: you lay down a rule, a condition or the law, not a body of proof.

Darwin's book sets its evidence before the reader, so laid out a treasure of substantiation is the fit — option (c).

Why the others are wrong

• (a)
  laid away a treasure of substantiation — Lay away means to put something aside for later, or in a shop to reserve goods against a deposit. Evidence stored away is the opposite of evidence presented.
• (b)
  laid about a treasure of substantiation — Lay about means to strike out wildly in all directions, as in he laid about him with a stick. It describes violence, not the setting out of proof.
• (d)
  laid into a treasure of substantiation — Lay into means to attack someone in words, to criticise harshly. Its object is a person being scolded, not a treasure of substantiation.

A phrasal verb is the verb plus its particle, and the particle carries the meaning. Lay out, lay down, lay off, lay away and lay into do not mean the same thing.

A substitution item like this keeps the verb fixed and changes only the particle, so the whole decision is which sense the sentence needs.

Here it needs evidence presented in an ordered way, and that sense belongs to lay out.

Key facts

• Lay out means to present or explain something clearly and in detail.
• Lay down means to state a rule or principle formally, as in lay down the law.
• Lay into means to attack or criticise someone harshly.

Common traps

• Assuming the underlined segment can only be wrong on grammar, when here it is idiom.
• Accepting laid down because it sounds formal and academic.
• Judging by the noun phrase treasure of substantiation instead of by the particle.

No directly related past PYQ was found.