脾为“气血生化之源”的理论基础是（）
A.气能生血
B.人以水谷为本
C.脾主升清
D.脾能运化水谷
E.脾为后天之本
参考答案：D
Beer is the most popular drink among male drinkers which overall consumption is significantly higher than that of women.
当三相全控整流桥控制角（）时进入逆变运行状态。
A、大于90°
B、小于90°
C、等于90°
D、等于80°
