如何在FPDF中自动调整单元格中的文本？

I’m using FPDF with PHP to generate reports. When the text is too long, it overflows. How can I stop this?

$string = "IT IS TOO LONG IT IS TOO LONG IT IS TOO LONG IT IS TOO LONG IT IS TOO LONG IT IS TOO LONG";
       $pdf->Cell(190,10,'Observations: '.$string.'',0,0,'C');