下述原发性支气管肺癌临床表现中，最常见的早期症状是()
A．咳嗽
B．咯血
C．胸痛
D．呼吸困难
E．发热
参考答案：A
地高辛的半衰期是36h，估计每日给药1次，达到稳态血药浓度的时间应该是：
A．24hB．6～7dC．48hD．36hE．2d
The Diaoyu islands have been part of China’s territory since ancient times, ______ as important fishing grounds of Taiwan.
A．served
B．to serve
C．serving
D．having served
