以下选项，除了（）以外，其他均为选煤厂的主要产品。
A、末原煤
B、洗块煤
C、煤泥
D、洗末精煤
参考答案：C
My parents are always telling me to leave everything in the study_________.
A．as they were
B．as it was
C．like they were
D．like it was
下列物质中缩血管作用最强的是______
A．内皮素 B．肾素C．血管紧张素Ⅱ D．组胺E．肾上腺素
