Select the most appropriate option to fill in the blank.
The researcher ______ the same hypothesis since his doctoral work began.
Answer और ExplanationAnswer and explanation
Answer: (B) has been testing
Concept (Present Perfect Continuous with Since): जब कोई कार्य अतीत में आरम्भ होकर अब तक जारी हो और वाक्य में 'since' से आरम्भ का समय बताया गया हो, तब Present Perfect Continuous (has/have been + V-ing) का प्रयोग होता है। 'since his doctoral work began' यही संकेत देता है, इसलिए 'has been testing' सही है।
✓ Correct sentence: The researcher has been testing the same hypothesis since his doctoral work began.
विकल्प (a), (c) और (d) के Future (भविष्य) या Simple Present रूप 'since' के साथ नहीं चलते।
Exam trap: 'since' के साथ 'has tested' या Simple Present को सही मान लेना ही वह जाल है।
Concept (Present Perfect Continuous with Since): when an action began in the past and is still continuing, and the sentence gives its starting point with 'since', the present perfect continuous (has/have been + V-ing) is used. 'Since his doctoral work began' gives this signal, so 'has been testing' is correct.
✓ Correct sentence: The researcher has been testing the same hypothesis since his doctoral work began.
Options (a), (c) and (d), with future or simple present forms, do not go with 'since'.
Exam trap: choosing 'has tested' or the simple present with 'since' is the trap.
Source: DSSSB ASO 2026 · 28 Sep 2026 · Shift III। Solution: Prashant Sir, Ramban।Source: DSSSB ASO 2026 · 28 Sep 2026 · Shift III. Solution by Prashant Sir, from Ramban.