高压氧对血液系统的影响主要包括()
A．红细胞减少
B．细胞沉降率加快
C．白细胞增加
D．凝血时间延长
参考答案：A, B, C, D
Read and write.（根据所给提示，填写正确的内容）
Chen Jie: What's your favourite season?
Sarah: I like s _ .
Chen Jie: Why do you like spring?
Sarah: Because I p _____ trees and fly kites. How about you?
Chen Jie: My f_____ season is summer.
Sarah: Why do you like it?
Chen Jie: Because I like eating i _ _ and swimming.
简述通信网的三要素。
