Section: Critical Reading Section 2

100) (1)By tracing the source of artifacts found in Europe, researchers (2)determined that the pattern of Viking settlements (3)were (4)generally similar, but varied in response to different climates.

1. By tracing
2. determined
3. were
4. generally
5. No Error

The intervening phrase of Viking settlements and lifestyles interrupts the subject and verb. The singular subject pattern doesn’t agree with the plural verb were.