硝酸甘油连续使用2～3周可出现耐受性，克服的方法是______和______等。
参考答案：采用小剂量给药 采用间歇给药
Jade is the highest award in Chinese culture and medals are the most important prize in Olympics，so medals with jade is the perfect ______ to present the Olympics in Beijing.
A．combination
B．cooperation
C．connection
D．composition
