.all IE{property:value\9;}.gte IE 8{property:value\0;}.lte IE 7{*property:value;}.IE 8/9{property:value\0;}.IE 9{property:value\9\0;}.IE 7{+property:value;}.IE 6{_property:value;}.not IE{property//:value;}lte：就是Less than or equal to的简写，也就是小于或等于的意思。lt ：就是Less than的简写，也就是小于的意思。gte：就是Greater than or eq
