Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

[EX Q]: According to the United States Department of Labors Bureau of Labor Statistics, there were approximately 210,900 physical therapists employed in the United States in 2014, earning an average $84,020 annually in 2015, or $40.40 per hour, with 34% growth in employment projected by the year 2024. The Bureau of Labor Statistics also reports that there were approximately 128,700 Physical Therapist Assistants and Aides employed in the United States in 2014, earning an average $42,980 annually, or $20.66 per hour, with 40% growth in employment projected by the year 2024. To meet their needs, many healthcare and physical therapy facilities hire "travel physical therapists", who work temporary assignments between 8 and 26 weeks for much higher wages; about $113,500 a year. Bureau of Labor Statistics data on PTAs and Techs can be difficult to decipher, due to their tendency to report data on these job fields collectively rather than separately. O-Net reports that in 2015, PTAs in the United States earned a median wage of $55,170 annually or $26.52 hourly, and that Aides/Techs earned a median wage of $25,120 annually or $12.08 hourly in 2015. The American Physical Therapy Association reports vacancy rates for physical therapists as 11.2% in outpatient private practice, 10% in acute care settings, and 12.1% in skilled nursing facilities. The APTA also reports turnover rates for physical therapists as 10.7% in outpatient private practice, 11.9% in acute care settings, 27.6% in skilled nursing facilities.
[EX A]: What group has the highest percentage of vacancy for Physical Therapist Assistants?

[EX Q]: SET domain methyltransferases deposit methyl marks on specific histone tail lysine residues and play a major role in epigenetic regulation of gene transcription. We solved the structures of the catalytic domains of GLP, G9a, Suv39H2 and PRDM2, four of the eight known human H3K9 methyltransferases in their apo conformation or in complex with the methyl donating cofactor, and peptide substrates. We analyzed the structural determinants for methylation state specificity, and designed a G9a mutant able to tri-methylate H3K9. We show that the I-SET domain acts as a rigid docking platform, while induced-fit of the Post-SET domain is necessary to achieve a catalytically competent conformation. We also propose a model where long-range electrostatics bring enzyme and histone substrate together, while the presence of an arginine upstream of the target lysine is critical for binding and specificity. This article can also be viewed as an enhanced version in which the text of the article is integrated with interactive 3D representations and animated transitions. Please note that a web plugin is required to access this enhanced functionality. Instructions for the installation and use of the web plugin are available in Text S1.
[EX A]: What is the characteristic domain of histone methyltransferases?

[EX Q]: Kiss crisis, hug horrors and the UK's handshake headaches Greeting someone, saying goodbye - these situations fill me with unease. You have a second to make a dangerous decision. One peck ? Two pecks? Three? No kisses at all? Why, I think, as I crash into the other person's face, why can't it be as simple as a handshake? A survey by the soap company Radox in May showed one in five Brits now feels a handshake is "too formal", according to the Daily Mail. Some 42 percent said they never shook hands when greeting friends. For one third of people the alternative was a hug, for 16 percent a kiss on the cheek. British people are known to be reserved - unfriendly, some would say. Handshakes used to work for us because we didn't have to get too close. But the super-British handshake is no longer fashionable. We want to be more like our easygoing Mediterranean neighbors who greet each other with kisses and hugs. The trouble is, we still find it a bit awkward. What does a married man do when greeting a married female friend, for example? How should someone younger greet someone older? Guys don't tend to kiss one another; my male friends in Britain go for the "manly hug", taking each other stiffly in one arm and giving a few thumps on the back with words like "Take it easy, yeah?". The biggest questions, if you do decide to kiss, are how many times and which cheek first. Unlike the French, who comfortably deliver three, our cheek-pecks usually end in embarrassed giggling : "Oh, gosh, sorry, I didn't mean to kiss you on the lips, I never know where to aim for first!" But then it's never been easy for us poor, uncomfortable Brits. Even the handshake had its problems: don't shake too hard, but don't hold the other person's hand too limply either, and definitely don't go in with sweaty hands. Maybe it's better to leave it at a smile and a nod.
[EX A]:
Which does the author think might be the safest form of greeting for a British person?