钩藤不宜久煎的原因是
A．气味芳香B．质地疏松C．药性发散D．药效降低E．含挥发油
参考答案：D
解析：钩藤久煎则平肝及降血压功效降低，故不宜久煎。
Ms. Claire is a strict but kind teacher, _____ who, usually, _____ her students.
A．ones; are liked by
B．one; are liked by
C．ones; is popular among
D．one; is popular with
确证汽油是混合物的一种方法是（ ）
A．测量密度
B．闻气味
C．测量沸点
D．将它燃烧
