I finally found the solution :
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QUESTION
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<text sometext>
/ items = text
/ fontstyle = ("Academy Engraved LET", 2.12%, false, false, false, false, 5, 0)
/ txcolor = (0, 0, 0)
/ position = (50, 40)
</text>
<item text>
/1 = "Donnez la valeur du point situé sur ce segment :"
</item>
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PICTURE
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<picture NumberPicture>
/ items = NumberItems
/ select = noreplace
/ position = (50%, 30%)
</picture>
<item NumberItems>
/1 = "8.jpg"
/2 = "-14.jpg"
/3 = "52.jpg"
/4 = "-43.jpg"
/5 = "77.jpg"
/6 = "10.jpg"
/7 = "-8.jpg"
/8 = "-21.jpg"
/9 = "57.jpg"
/10 ="22.jpg"
/11= "62.jpg"
/12= "-50.jpg"
/13= "33.jpg"
/14= "-31.jpg"
/15= "-68.jpg"
/16= "-75.jpg"
</item>
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BLOCKS
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<block PictureQ>
/ trials = [1-16=myopenended]
</block>
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AUTRES
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<openended myopenended>
/ stimulusframes = [1=NumberPicture, sometext]
/ buttonlabel = "suivant"
</openended>
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Data Columns
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<data>
/ columns = [date, time, subject, stimulusitem, response]
</data>
Mandy,