若x=1是方程x2﹣5x+c=0的一个根,则这个方程的另一个根是( )
A:﹣2
B:2
C:4
D:﹣5
下列有关肺泡适于进行气体交换特点的叙述正确的是.( )
①肺泡数量很多 ②肺泡外面包绕着丰富的毛细血管
③肺泡壁和毛细血管壁都是由一层上皮细胞构成 ④肺泡分布广泛.
A
The Double Ninth Festival is a traditional (传统的)Chinese festival. It usually comes in October or November. On this day,people always wear the zhuyu (茱萸)plant. They usually climb mountains. Sometimes they go to see flower shows. The Double Ninth Festival is a festival for old people. People usually visit their parents and grandparents on this day. They often eat Double Ninth cakes together.