题目

阅读理解That little awith a circle around it that is found in e-mail addresses is most commonlyreferred to as the at symbol. Surprisingly though, there is noofficial, universal name for this sign. There are lots of strange terms todescribe the @ symbol.Before it became the fixedsymbol for e-mail, the symbol was mostly used to represent the cost or weightof something. For instance, if you bought 6 apples, you might write it as 6apples @ $1.11 each.With the introduction ofe-mail came the popularity of the @ symbol. The @ symbol separates a person'sonline user name from his mail server addres空间几何体的三视图如图所示，则此空间几何体的直观图为（ ）A．B．C．D．