Assuming that Li Chen 15 answers all the questions correctly, she should get: 15× 10= 150 (points).

Now I get 88 points, but less: 150-88=62 (points),

Because every wrong question will be deducted 4 points, and no answer will get 0 points, so every wrong question will be * * * less: 10+4= 14 (points).

If you don't answer, you will get 0, that is, if you don't answer a question, you will get 0+ 10= 10 (points).

Because: 62÷ 14=4 (topic) ... 6 (minute) 6 is not a multiple of 10, which is irrelevant.

62÷ 14=3 (question) ... 20 (minute), which is a multiple of 10, and meets the question.

The unanswered questions are: 20÷ 10=2 (question).

She has two unanswered questions.

So the answer is: 2.