痰热互结，症见胸脘痞闷，按之则痛，舌苔黄腻，脉滑数者，治宜选用（）
A．温胆汤
B．清气化痰丸
C．茯苓丸
D．半夏白术天麻汤
E．小陷胸汤
参考答案：E
分解因式：x2-y2=（ ）。
(2010·上海)Wind power is an ancient source of energy ________ we may return in the near future.
A．on which
B．by which
C．to which
D．from which
