Although the plan sounded perfect in theory, it proved to be difficult to execute _________ practice.

0
writing

Which choice completes the text so that it conforms to the conventions of Standard English?

A

on

B

with

C

in

D

by

Correct Answer: C

Choice C is the best answer. The correct idiomatic pair is "in theory" and "in practice."

Choice A is incorrect because "on practice" is not the correct idiom. Choice B is incorrect because "with practice" changes the meaning to "by practicing." Choice D is incorrect because "by practice" is not the correct idiom.