患者,女,30岁。胃脘胀痛,牵连胁痛,嗳气频频,舌苔薄白,脉弦。用药宜首选()
A.柴胡、青皮
B.陈皮、枳壳
C.木香、砂仁
D.苍术、厚朴
E.藿香、佩兰
参考答案:A
某元素R的氯化物的化学式为RCl3,若在化合物中R的化合价不变,R的氧化物的化学式为______,R的氢氧化物的化学式为______.
Peter has ____ good friends. But ____ of them can speak English.[ ]
A. few, a few
B. a few, few
C. little, a little
D. a little, little