Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

[EX Q]: Few studies investigated the best method for removing stains from different types of resin-based composite restorations and compared them to the more recently introduced nanocomposites. This study compared the effect of four methods for stain removal from composite resins; finishing with Sof-lex disks, using pumice and brush, bleaching with 10% carbamide peroxide and 38% hydrogen peroxide.', 'Twenty disk specimens were prepared. Specimens were immersed in a staining solution for 3\xa0weeks. The stained surfaces of five specimens from each RBC material were treated with one of the treatment procedures. Colorimetric measurements were taken using spectrophotometer prior to and after staining, and then repeated after surface treatments. Color difference values were calculated.', "One-way ANOVA indicated significant differences in color change of the three composite resin materials following staining. Filtek Z250 showed the least susceptibility to discoloration followed by Renamel, Filtek Supreme was the material most prone to discoloration. Two-way ANOVA and Tukey's Post Hoc showed that all stain removing procedures except polishing with pumice, were able to return Filtek Z250 to clinically acceptable color difference. While bleaching with 38% carbamide peroxide was not effective with Renamel. Only pumice and 10% carbamide peroxide were able to return Renamel to clinically acceptable color difference.
[EX A]: Do the effectiveness of four methods for stain removal from direct resin-based composite restorative materials?

[EX Q]: Williams syndrome (WS), a genetic disorder resulting from hemizygous microdeletion of chromosome 7q11.23, has emerged as a model for identifying the genetic architecture of socioemotional behavior. Common polymorphisms in GTF2I, which is found within the WS microdeletion, have been associated with reduced social anxiety in the general population. Identifying neural phenotypes affected by these polymorphisms would help advance our understanding not only of this specific genetic association but also of the broader neurogenetic mechanisms of variability in socioemotional behavior.', 'Through an ongoing parent protocol, the Duke Neurogenetics Study, we measured threat-related amygdala reactivity to fearful and angry facial expressions using functional magnetic resonance imaging, assessed trait personality using the Revised NEO Personality Inventory, and imputed GTF2I rs13227433 from saliva-derived DNA using custom Illumina arrays. Participants included 808 non-Hispanic Caucasian, African American, and Asian university students.', 'The GTF2I rs13227433 AA genotype, previously associated with lower social anxiety, predicted decreased threat-related amygdala reactivity. An indirect effect of GTF2I genotype on the warmth facet of extraversion was mediated by decreased threat-related amygdala reactivity in women but not men.
[EX A]: Does a Common Polymorphism in a Williams Syndrome Gene predict Amygdala Reactivity and Extraversion in Healthy Adults?

[EX Q]: Although uncommon, hearing loss after spinal anesthesia has been described. Vestibulocochlear dysfunction after spinal anesthesia in which 22-gauge and 25-gauge Quincke needles were used was investigated to determine if needle size affected hearing.', 'Patients with American Society of Anesthesiologists physical status I and II, aged 20 to 40 years, who were undergoing lower extremity surgery under spinal anesthesia were randomized into 2 groups. After intravenous hydration, 3 mL of 0.5% bupivacaine was administered for spinal anesthesia, which was performed with a 22-gauge Quincke needle in group I (n=30) patients and a 25-gauge Quincke needle in group II (n=30) patients. Before surgery and 2 days after surgery, pure-tone audiometry and tympanometry were performed. Preoperative and postoperative hearing data were obtained in the right and left ears for every frequency. Headache, nausea, and vomiting and cranial nerve III, IV, V, VI, VII, and VIII function were assessed on postoperative day 2.', 'Demographic data were not different between the groups. No hypoacousis was noted at any frequency during the entire testing period in either group. Two patients from group I experienced postdural puncture headache on postoperative day 3, and neither had hearing loss. No patient had cranial nerve dysfunction.
[EX A]:
Does hearing loss occur in young patients undergoing spinal anesthesia?