Zhang Yining has trained continuously for six hours. ______ she is tired out.

A．There is no wonder

B．There is no need

C．It’s no wonder

D．It’s no doubt

（5分）右图为三种血管关系示意图，请你据图回答下列问题：

（1）写出图中标号所示血管名称：① _________② _________ ③_________

（2）血液在标号_________处流动最快，红细胞在标号②所示血管内呈单行通过，该血管管壁只由 _________扁平上皮细胞构成，管内血流速度最慢。这些特点便于血液与组织细胞进行物质交换。