由已知可得log2x≥2x＞0，解不等式可得{x|x≥4}
故答案为：[4，+∞）
指出句子中的错误并改正。
我们的报刊、杂志、电视和一切出版物，更有责任作出表率，杜绝用字不规范的现象，增加使用语言文字的规范意识。
A fire is discovered in the forepeak of a vessel at sea. The wind is from ahead at 35 knots.You should（）.
A.remain on course and hold speed
B.change course and put the stern to the wind
C.change course to put the wind on either beam and increase speed
D.remain on course but slack the speed
