Now I've been sort of banging on about this for the last couple of months, 在过去的几个月里，我反复在讨论这个问题， and people sometimes say to me, "Well Tim, it's kind of obvious. Obviously trial and error is very impor
I began helping a family in the Karoo Desert in the 1970s turn the desert that you see on the right there back to grassland, 20世纪70年代我开始帮助一个在卡鲁沙漠的家庭，你们看到在右边沙漠变回了草地， and thankfully, now their grandchil
On the 75th anniversary of Social Security, President Obama promises to protect it from Republican leaders in Congress who have made privatization a key part of their agenda. He makes clear that, espe
March 3, 2008 THE PRESIDENT: Welcome. Thanks for coming. Mr. Vice President, Mr. Secretary, members of the Dakotan Congressional Delegations, Senator from Alaska, other members of Congress, Members of
