温带草原在半干旱区的群落类型是 ( )
A．草甸草原
B．典型草原
C．荒漠草原
D．高山草甸
参考答案：B
In the face of all these difficulties,we're not discouraged and __________ good spirits. [ ]
A. keep up
B. go up
C. hold up
D. pick up
解热镇痛药的正确服药时间是：（）
A、空腹
B、饭前半小时
C、饭后半小时
