主含皂苷，苷元为齐墩果酸的药材是（）
A.牛膝
B.白芍
C.人参
D.威灵仙
E.甘草
参考答案：A, C, D
A laborer is paid $8 per hour for an 8-hour day and times that rate for each hour in excess of 8 hours in a singe day. If the laborer received $ 80 for a single day’s work, how long did he work on that day ？（）
A.6hr. 40min.
B.9hr. 20min.
C.9hr. 30min.
D.9hr. 40Min.
E.10hr.
发现高压加热器管束泄漏，可根据（）高低停用高加。
times that rate for each hour in excess of 8 hours in a singe day. If the laborer received $ 80 for a single day’s work, how long did he work on that day ？（）