我国自行设计的第一座自升式钻井平台“渤海一号”是（）生产的。
A.江南造船厂
B.沪东造船厂
C.大连造船厂
D.广州造船厂
参考答案：C
Rainforests _____ and burned at such a speed that they will disappear from the earth in the near future. [ ]
A. cut
B. are cut
C. are being cut
D. have been cut
慢性肾衰竭声像图表现为：①肾皮质回声增高，大于脾回声；②肾锥体回声增强导致皮髓质界限不清；③CDFI示轻者呈边缘缺损型，重者显示呈星点型和无血流型；④多普勒频谱显示肾动脉血流呈低速高阻型（）
A.①②③
B.①③
C.②④
D.④
E.①②③④
