双向锁定封隔器由芯轴和()分别带有左、右旋金属齿形螺纹的锁块组成。
A、一对
B、二对
C、三对
D、四对
参考答案:B
Yunnan province in China was attacked by such a terrible drought this early spring ____________few people had experienced before, ____________ made us worry about global climate changes.
A.that; that
B.as; which
C.which; it
D.when; as
患者女性,60岁,反复咳嗽、咳痰10余年,每年冬季发作3个月以上。查体:桶状胸,双肺叩诊过清音,呼气音延长。
不可能出现的体征是
A.肺泡呼吸音增强
B.肝浊音界下移
C.双肺满布湿啰音
D.心浊音界消失
E.双肺散在干啰音