One way to do this would be to create a separate questionnaire for each of these items. Then set a time limit for the questionnaire using a duration parameter when you list the que file in the experiment file.

Or another solution..

You could use essay items instead of instruction items for presenting your info. Use the duration parameter of d10 and move the essay text area off screen by using a top parameter like (t1000,d10). The question wording would be like using an instruction item but it would give you the option of telling subjects they can press ESC to quit the item if they are done reading before the time limit.