In the following sentence, one numbered part may contain a grammatical error, or the sentence may be fully correct. Choose the number of the part that has an error, or choose option (4) for No Error. Sentence: The professor recently describes 1500 tests (1) / in which blind people passed with greater (2) / ease than those who could see. (3)

Introduction / Context:
This question tests the learner's understanding of tense consistency, particularly when an adverb of time such as recently appears. The sentence describes what the professor did in the recent past and therefore must use an appropriate past tense. Correct alignment between time markers and verb forms is a fundamental aspect of English grammar.

Given Data / Assumptions:

• The sentence is divided into three numbered segments, plus a No Error option.
• Part (1) contains the phrase The professor recently describes 1500 tests.
• Part (2) explains the content of the tests: in which blind people passed with greater.
• Part (3) finishes with ease than those who could see.

Concept / Approach:
The key concept is choosing the correct tense. The adverb recently usually triggers the simple past tense in statements about completed actions, for example The professor recently described 1500 tests. Using the simple present describes here conflicts with the sense of a finished action that took place in the recent past. Therefore, the correct form should be described, not describes. The error lies in part (1).

Step-by-Step Solution:
Step 1: Read part (1): The professor recently describes 1500 tests. The presence of recently suggests that the action happened not long ago but is now complete.Step 2: Realise that for a completed past action, especially one indicated by recently, English uses the simple past form: described.Step 3: Check part (2): in which blind people passed with greater. This phrase correctly describes the test results and uses the past tense passed.Step 4: Check part (3): ease than those who could see. This part is also grammatical, contrasting blind people with those who could see.Step 5: Since only part (1) has a tense problem, identify it as the segment containing the error.Step 6: Mentally correct the sentence as The professor recently described 1500 tests in which blind people passed with greater ease than those who could see.

Verification / Alternative check:
A quick verification method is to try replacing recently with a time expression like yesterday or last year. The sentence The professor yesterday describes 1500 tests sounds clearly wrong, whereas The professor yesterday described 1500 tests sounds normal. Because these adverbs behave similarly, the form described must be correct with recently as well. Another check is to note that the rest of the sentence uses past tense verbs passed and could see, which aligns naturally with described in the simple past.

Why Other Options Are Wrong:
Option 2: Part (2) is grammatically correct. It uses past tense passed, which is appropriate for describing what happened in the tests.Option 3: Part (3) correctly continues the comparison with ease than those who could see and does not introduce any tense or agreement errors.Option 4: Because part (1) clearly contains an error, it is not correct to say that the sentence has no error.

Common Pitfalls:
Some learners overlook the time adverb recently and focus only on the logical meaning of the sentence. Others may think that present tense describes is acceptable because professors may still be describing these tests on various occasions. However, the presence of recently and the narrative feel of the sentence indicate a completed action, not a habitual one. Practising the link between time expressions and tenses helps prevent these mistakes.

Final Answer:
The wrong tense appears in the first segment, so the correct option is 1.