双子叶植物茎的初生维管束包括初生木质部和初生韧皮部。( )
参考答案:错
绩效报告的步骤包括收集并分发有关项目绩效的信息给项目干系人,这些步骤包括进度和状态报告、预测等。以下关于绩效报告的说法,______是错误的。
A.状态报告介绍项目在某一特定时间点上所处的位置,要从达到的范围、时间和成本三项目标上讲明目前所处的状态
B.进度报告介绍项目组在一定时间内完成的工作
C.绩效报告通常需要提供有关范围、进度、成本和质量的信息
D.状态报告除了需要列出基本的绩效指标,同时需要分析进度滞后(或提前)和成本超出(或结余)的原因
Ants first captured the attention of software engineers in the early 1990s. A single ant cannot do much on its own, but a group of ants (52) can solve complex problems. That inspired people like Marco Dorigo, who is one of the founders of a (53) known as group intelligence.
Ants are good at choosing the shortest possible route between a food (54) and their nest. This reminds us of a classic computational travelling-salesman problem. Given a list of cities and their (55) apart, the salesman must find the shortest route needed to visit each city once. As the number of cities (56) , the problem gets more complicated.Ants solve their own problem using chemical signals called pheromones (信息素), when an ant finds food, she takes it back to the nest, (57) a pheromone trail that will attract others. The more ants that (58) the trail, the per it becomes. (59) , the pheromones evaporate (挥发) quickly, so once all the food has been collected, the trail soon goes cold. This rapid evaporation means long trails are less (60) than short ones, all else being equal. Pheromones thus turn the (61) intelligence of the individual ants into something more powerful.
54().
A. range
B. source
C. chain
D. origin