Lying on the table next to the microphones and tape recorders at yesterday's press conference was a piece of paper reminding Professor Cheng how to respond. 'Be calm. Be positive. Be patient . . . Listen before answering. If in doubt, stick to the statement . . . Do not digress,' it read. With about 150 reporters, photographers and cameramen in the room, the advice was nothing less than a lifebelt. Professor Cheng, who said he had been ill, had to ask repeatedly for questions to be repeated, complaining it was too noisy. And there were jeers from reporters when university spokesman Rupert Chan Kwan-yun, having said Professor Cheng would answer questions for only 15 minutes, outlined at length - and in two languages - the rules to be followed when asking a question. And he meant business. At one point, he told a reporter to leave because he had tried to speak when another question was already being asked. The reporter did not comply.