Microsoft chairman Bill Gates used his last appearance before the US House of Representatives to send a warning signal to legislators over the US state of innovation and competitiveness. Citing severe restrictions on immigration and the poor math and science performance of US students, Gates said American high-tech firms are in danger of losing their ability to develop innovative products. Appearing before the Committee on Science and Technology, he called for full funding of the America COMPETES Act and a lifting of the current cap on H-1B visas to allow foreign students studying in the US to remain and work there. During his comments before the Committee Gates noted that in 2007 Microsoft opened a facility in Vancouver and lauded the Canadian government for the superior way in which it treats highly skilled workers. Gates is slated to step down as chair of Microsoft this year to focus on his work with the Bill & Melinda Gates Foundation....