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