The prices of new houses in our city have been _______ than before, but they _______ well at present. [ ]

A. higher, still sell

B. lower, are not still sold

C. higher, don't sell

D. cheaper, are not still sold

早产儿易出现体温降低的原因是

A．肺发育不良
B．棕色脂肪少
C．棕色脂肪多
D．缺乏肺表面活性物质
E．肺表面物质增多所致