Arrange these parts so as to form a complete meaningful sentence/paragraph and…

Correct answer: Q S P R

Reconstructed sentence: The delay meant that not only did the monster tsunami wave strike without warning but that even five hours later there was no proper estimate of the true magnitude of the grave tragedy.

Explanation:

• The fragment that introduces the situation is the clause beginning "The delay meant that not only did the monster tsunami wave" (Q). This sets up a subject that needs an action.

• The clause "strike without warning but" (S) supplies the action of the wave and the contrastive conjunction that links to the following clause, so S must follow Q.

• The clause "that even five hours later there was no proper estimate" (P) completes the contrast introduced by "but" and requires the phrase "of the true magnitude of the grave tragedy" (R) to complete the object of "estimate."

Therefore the correct and grammatical order is Q S P R.

Why other orders fail: Orders that place the dependent phrase "of the true magnitude of the grave tragedy" (R) at the start leave it without the noun it modifies, and orders that put the estimate clause (P) immediately after the wave introduction (Q) leave the wave without its verb.