分子是保持原物质性质的最小微粒。
参考答案：错
— Why not sit in your own seat, Mary?
I can’t see the blackboard clearly because two tall boys are sitting _____ me.
A．next to
B．beside
C．in front of
D．opposite
银联跨行交易的测试工作每年应不少于（）次。
A、1
B、3
C、5
D、12
