城市主要供水的水源地，应在何处布设断面？
A、上游500m
B、上游1000m
C、下游500m
D、下游1000m
参考答案：B
邻甲基苯甲酸()有多种同分异构体，其中属于酯类，但分子结构中含有甲基和苯环的异构体有( )
A．2种
B．3种
C．4种
D．5种
The Baker Company uses the LIFO inventory valuation method and reported its inventory at $ 200000 and its COGS at $ 500000. The company’ s LIFO reserve increased from $ 5000 to $ 30000 during the year. What amounts would the company report if it were to use the FIFO methodEnding Inventory COGS（）
①A. $170000 $ 525000
②B. $ 230000 $ 475000
③C. $170000 $475000
)有多种同分异构体，其中属于酯类，但分子结构中含有甲基和苯环的异构体有( )