Senator DAY (South Australia) (14:41): Mr President, I ask a supplementary question. Israel is a world leader in water recycling and desalination and can produce desalinated drinking water at $830 a megalitre—comparable with Murray-Darling water prices in the drought and a third of the $2,400 a megalitre desalination costs in Adelaide. Israel is also a world leader in drip irrigation, which my home state has adopted to improve food production levels and Murray river health. What role will water technology trade play in future negotiations? Senator Wong: Mr President, I rise on a point of order. I read your note to senators, Mr President, which actually addressed the issue of supplementary questions and made the very salient point that the fact that you mention some aspect of subject matter which is the same does not make it a proper supplementary. I would suggest to you that it is not a supplementary question. The PRESIDENT: Thank you, Senator Wong. I will give the senator an opportunity to rephrase that question, but that question was not a supplementary question to the primary question. Senator DAY: The final point was: what role will water technology trade play in future negotiations? We are talking about a free trade agreement. What role will water play in free trade? The PRESIDENT: Senator Day, I will allow that question to stand, as I have in the past. It is borderline supplementary to the primary question. The primary question went into other matters in relation to other countries, not just the water in relation to Israel. But I will allow that to stand on this occasion. I urge all senators to be cautious in the framing of their supplementary questions.