Question

at the start of the twenty - first century ___ advances in computing that accelerated both computational scale and architectural innovation. for example, the 2002 valkyrie ai model developed at eth zürich surpassed 10 billion parameters, whereas the 2006 solis chip pioneered photonic switching to reduce energy consumption in server clusters.
19
mark for review
which choice completes the text so that it conforms to the conventions of standard english?
a was
b were
c is
d are

Explanation:

1. First, determine the subject and tense. The subject is "advances" (plural), and the context is the start of the 21st century (past time), so we need a plural past - tense verb.
2. Analyze each option:

• Option A: "was" is singular past - tense, which does not agree with the plural subject "advances".
• Option B: "were" is plural past - tense. It agrees with the plural subject "advances" and the past - time context (start of the 21st century).
• Option C: "is" is singular present - tense, which does not match the subject and the time context.
• Option D: "are" is plural present - tense, but the context is in the past (start of the 21st century), so it is not appropriate.

Answer:

B. were