Find the erroneous segment; if none, choose ‘‘No error.’’ Sentence: The patient recover so fast that the expert doctors also were surprised.

Introduction / Context:
The test targets verb form and agreement. The subject ‘‘The patient’’ is singular; the verb must agree and the tense should align with the context (past event surprising the doctors).

Given Data / Assumptions:

• Subject: singular (‘‘patient’’).
• Context: completed action signaled by ‘‘were surprised’’ (past).
• Verb given: ‘‘recover’’ (base form).

Concept / Approach:
Two acceptable corrections exist depending on the intended time: simple past ‘‘recovered’’ for a completed event, or present simple ‘‘recovers’’ for a habitual truth. The presence of ‘‘were surprised’’ strongly suggests a particular incident in the past; therefore ‘‘recovered’’ fits best.

Step-by-Step Solution:
Match number and tense: change ‘‘recover’’ → ‘‘recovered.’’Keep the result clause unchanged: ‘‘… so fast that … were surprised.’’Correct version: ‘‘The patient recovered so fast that the expert doctors were surprised.’’

Verification / Alternative check:
Try the present: ‘‘The patient recovers so fast that … were surprised’’—tense clash appears. Past ‘‘recovered’’ solves it.

Why Other Options Are Wrong:
B–D are grammatical once A is fixed.

Common Pitfalls:
Leaving the verb in base form after a singular subject; ignoring the time frame implied elsewhere in the sentence.

Final Answer:
The patient recover