液压系统中的溢流阀是一种（）。
A、流量控制阀
B、速度控制阀
C、方向控制阀
D、压力控制阀
参考答案：D
Zhou Libo is Shanghai's favorite funny man. He is good at making people laugh. His lively shows were
_____ hot that tickets sold out in minutes. [ ]
A. very
B. too
C. such
D. so
GFS系统中，主要的系统管理技术包含①大规模集群安装技术②节点动态加入技术③故障检测技术④节能技术中哪几个.（）
A.①②③
B.①③④
C.②③④
D.①②③④
