Sentence improvement (preposition with accustom): choose the best substitute for the underlined part in the sentence below. You must accustom yourself with new ideas.

Introduction / Context:
This question tests the correct preposition and structure used with the verb \"accustom\". Competitive exams frequently check whether you know standard verb preposition combinations like \"accustom to\", \"interfere with\", and \"depend on\". Using the wrong preposition quickly marks a sentence as ungrammatical.

Given Data / Assumptions:

• Sentence: You must accustom yourself with new ideas.
• The underlined part involves the phrase \"accustom yourself with\".
• Options vary in form and preposition: \"accustomed with\", \"accustom to\", \"accustom yourself to\", and \"No improvement\".
• The intended meaning is that you should become used to new ideas.

Concept / Approach:
The verb \"accustom\" is usually used in two ways:

• \"to accustom someone to something\"
• \"to accustom oneself to something\"

In both patterns, the correct preposition is \"to\", not \"with\". In the given sentence, since the reflexive pronoun \"yourself\" is already present, the most natural correction is \"accustom yourself to new ideas\".

Step-by-Step Solution:
Step 1: Note that \"yourself\" is already part of the sentence, so we are using the reflexive structure. Step 2: Recall the correct pattern: \"accustom yourself to something\". Step 3: Replace \"with\" by \"to\" and keep the reflexive pronoun: \"accustom yourself to new ideas\". Step 4: Compare with other possible structures and confirm that this one is the most complete and idiomatic.

Verification / Alternative check:
Test a few related sentences: \"Children quickly accustom themselves to a new school\", \"He soon accustomed himself to the climate\". In all these examples, the verb \"accustom\" is followed by \"to\". If you substitute \"with\" in those sentences, they sound foreign or wrong. This confirms that \"to\" is the only acceptable preposition in this pattern.

Why Other Options Are Wrong:
Option \"accustomed with\": \"Accustomed\" is the past participle or an adjective. Replacing \"accustom\" with \"accustomed\" would require restructuring the whole sentence, for example, \"You must be accustomed to new ideas.\" Moreover, the correct preposition is still \"to\", not \"with\". Option \"accustom to\": This omits the reflexive pronoun \"yourself\" and sounds incomplete in this specific sentence. The structure \"You must accustom to new ideas\" is not idiomatic. Option \"No improvement\": Keeping \"with\" maintains the incorrect verb preposition combination.

Common Pitfalls:
Learners often overuse \"with\" because it is very common in English and in many other languages as a preposition of association. However, many verbs require a specific preposition for historical and idiomatic reasons. Memorising these patterns together with the verb is essential for accurate usage in exams and formal writing.

Final Answer:
The correct version is: You must accustom yourself to new ideas. Hence, the correct option is accustom yourself to.