The world pattern is the relatively steady structure or system formed as a result of competition of all kinds of main powers of the world in a particular period.Since the 20th century,the world pattern has had three great changes:from Europe-centered pattern to the two-polar pattern,to multi-polar pattern.Today's world pattern is still being formed.Its basic structure is "one superpower and several major powers".Its development trend is "multipolarization".Its main feature is that "one superpower" coexists ...