Digital PSAT Reading and Writing Practice Question 253: Answer and Explanation
Question: 253
A few years ago, a research team at Fermi Lab known as the DZero Collaboration announced observations of matter-antimatter asymmetries on a scale never seen before. Prior to the DZero study, baryon asymmetry and similar CP violations _______________in laboratory settings only in much smaller—and thus, less helpful—orders of magnitude.
Which choice completes the text so that it conforms to the conventions of Standard English?
- A. has been observed
- B. have been observed
- C. had been observed
- D. is being observed
Correct Answer: C
Explanation:
C. This is an event that takes place prior to another event in the past, so “had” is needed. Choices A and B are in the past perfect tense, and choice D is in the present tense.
Test Information
- Use your browser's back button to return to your test results.
- Do more Digital PSAT Reading and Writing Tests tests.
More Tests
- Digital PSAT Reading and Writing Test 1
- Digital PSAT Reading and Writing Test 2
- Digital PSAT Reading and Writing Test 3
- Digital PSAT Reading and Writing Test 4
- Digital PSAT Reading and Writing Test 5
- Digital PSAT Reading and Writing Test 6
- Digital PSAT Reading and Writing Test 7
- Digital PSAT Reading and Writing Test 8
- Digital PSAT Reading and Writing Test 9
- Digital PSAT Reading and Writing Test 10
- Digital PSAT Reading and Writing Test 11
- Digital PSAT Reading and Writing Test 12
- Digital PSAT Reading and Writing Test 13
- Digital PSAT Reading and Writing Test 14
- Digital PSAT Reading and Writing Test 15
- Digital PSAT Reading and Writing Test 16
- Digital PSAT Reading and Writing Test 17
- Digital PSAT Reading and Writing Test 18
- Digital PSAT Reading and Writing Test 19
- Digital PSAT Reading and Writing Test 20