先通读下面的短文，然后根据短文内容和所给首字母，在空格内填入一个适当的单词，使短文意思完整。所填单词必须在答题卡标有题号的横线上完整写出。

    Have you ever tried the "Magic Cube"(魔方) ? Pick up one of these cubes and you probably won't be able to p_______ (1) it down. How hard can it be to rearrange the nine little s_______(2) on each side of the cube? In fact, there are millions of possibilities! It has been over 30 years since the cube first h_______(3) the market. However, not many people know that it was used just as a simple classroom m_______(4) at the beginning.

    In 1974, Mr. Erno Rubik i_______(5) the "Magic Cube" as he called it. He did this to help his students u_______(6) difficult 3D concepts(概念). This classroom example was quickly t_______(7) into a popular toy. In 1979, Ideal Toys started to sell it as "Rubik's Cube". The invention quickly became a 1980s c_______(8) icon.

     As time went by, the cube once l_______(9) its attractive qualities. However, it made a comeback with the internet. Now anyone can go online and find many videos that show ways to s_______(10) the cube. Erik Akkersdijk of the Netherlands holds the world record now. He finished in just 7.08 seconds!

It is reported that two schools, ______ are being built in my hometown,will open next year. [ ]

A. they both

B. which both

C. both of them

D. both of which