请从方框中选择合适的单词填入短文中，使其意思完整（每词限用一次，其中有两个

多余选项）。

classroom, playground, tired, down, small, gives, lying

     We are in the    l    now. We are having a PE lesson. Mr Smith   2   us some orders. Look, we

are jumping up and   3   ten times. David can't do it, because he is too   4  . So he is   5   on the

grass now, having a rest.

复苏的生存链包括以下几个环节()

A．早期心肺复苏

B．早期求救

C．早期识别

D．早期高级心血管生命支持

E．早期除颤