BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach Starts Oct 17
Chris Peckover, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Chris Peckover, 100th-Percentile GMAT Scorer

Oct 17 · Chris Peckover
Sat · 11:00 AM to 2:00 PM ET
Oct 20 · Chris Peckover
Tue, Thu · 8:00 to 10:00 PM ET
Oct 25 · Josh Braslow
Sun · 1:00 to 4:00 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemand 5 seats left Start anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Although malaria was once universally believed to have been introduced to Native American populations by 16th-century

Expert replies
by BTGmoderatorDC » Sun Mar 07, 2021 2:36 am

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty—

Although malaria was once universally believed to have been introduced to Native American populations by 16th-century European explorers, the recent excavation of a 10th-century mass grave of Native American malaria victims has caused many historians to reconsider their chronologies of European incursion into the Americas.


(A) malaria was once universally believed to have been

(B) malaria was at one time universally believed as being

(C) malaria, once universally believed to be

(D) malaria was at one time universally believed as having been

(E) malaria, once universally believed as being


OA A

Source: Princeton Review
Join the discussion
Source: — Sentence Correction |

This sentence is correct as it is written because it makes use of the correct verb tense have been.' It also contains the idiom 'believe to' in order to explain that scientist believes that malaria was once believed to have been introduced by 16th-century European explorers.

Option A - correct
This answer choice uses the correct verb tense which is the present perfect tense 'have been' and the correct idiom 'believed to.'

Option B - incorrect
This option is incorrect states that the present progressive form of the verb 'as being' adds an incorrect notion to the sentence. Furthermore, it explains that 16th-century people are currently introducing malaria. In addition, one time means numerically just one time and not other times. The sentence calls for the present perfect tense, and the idiom structure believed.... as is incorrect.

Option C - incorrect
The use of the present tense verb 'be' is not correct. The former belief in this sentence concerns an occurrence in the past, therefore, the sentence calls for the present perfect tense.

Option D - incorrect
This option incorrectly states believed as having been. The sentence calls for the present perfect tense, and the idiom structure believed. Furthermore, it connotes the same meaning as option B.

Option E - incorrect
this incorrectly stated believed as being. However, the sentence calls for the present perfect tense and the idiom structure 'believed.'
Join the discussion

• Page 1 of 1