要了解某市第二季度棉布生产的基本情况，调查年产量最大的几家棉纺厂，这种调查属于重点调查。
参考答案：对
I didn’t know __________. Can you tell me?
A．who to speak to
B．who speak to
C．who to speak
D．who spoke
目前临床最常用的MRI对比剂是
A．Mn-DPDFB．Gd-DTPAC．Gd-EOB-DTPAD．SPIOE．USPIO
