stimulus lists

I have two stimulus lists one containing 30 pictures the other 50 statements both randomised.

Of the 50 statements I only want to present 30, is this possible?

So experiment displays a pic, statement, pic, statement … but I want it to move on to the next event after the 30th statement and not go onto the 31st statement.

Using SuperLab 4.5.

Thanks in advance

Do you want a statement to always follow a picture, or vice versa? Do the statements and sentences need to be shown as pairs, or are they randomized?