B

    These days, we see a lot of shopping festivals(节日). Singles' Day is a big one for Chinese shoppers. It's on November 11^th(11月11日). In the US, Black Friday is the most well-known one.

    Black Friday is always on the day after the Thanksgiving holiday(感恩节). On this day, stores(商店) give special deals(特价). Shoppers get up very early. They wait in line in front of the stores at 2 or 3 am before the stores open. Sometimes there are too many people. They can't get inside the store. Black Friday is not the only shopping festival in the US. Another one is CyberMonday(网络星期一). This day is always on the Monday after Thanksgiving.

    Personally, I don't like these holidays, because they put too much importance（重要性）on buying things. And that's a trend of over-consumption(过度消费). What do you think of these holidays?

扩句

①小孩玩耍。

②我们看到了细菌。

如图，竖直放置、开口向上的试管内用水银封闭一段理想气体，若大气压强不变，管内气体（  ）