领导者的职责就是领导者为实现领导职能而应承担的责任和所要做的工作，是领导者在履行职权的过程中所必须尽的义务。
参考答案：对
若向量a、b满足|a|=|b|=1，a与b的夹角为120°，则a·a+a·b=（ ）。
The French visitor’s English was so poor that he found it difficult to make himself (understand)（）.
