We need to … for lost ground.

Analyze the question: The sentence is "We need to __ for lost ground." We need a phrasal verb that means to compensate for something lost or missed.

Explain the concept: The idiom is "make up for", meaning to compensate for something lost, missed, or neglected. For example:

• "He worked extra hours to make up for lost time."
• "The team must make up for lost ground in the second half."

"Lost ground" means progress or advantage that has been lost. To recover it, you "make up for" it.

Solution, step by step:

1. The blank must be followed by "for", so the phrasal verb must combine with "for".
2. Check each option: • A. make in for: not an English expression. • B. make by for: not an English expression. • C. make up for: correct. It means to compensate or recover. • D. make through for: not an English expression.
3. Only "make up for" is a standard idiom that fits the meaning.

Complete sentence: "We need to make up for lost ground."

Tip: Learn common phrasal verbs with "make": make up for (compensate), make out (understand or see), make off with (steal), make do with (manage with what is available). "Lost ground", "lost time", and "lost opportunity" almost always go with make up for.