根据下面16个任务，点击消去方框内的铅笔，使剩下的铅笔所组成的正方形达到任务的要求，其中正方形可以由4根，8根或12根铅笔组成，并且要保证每一支铅笔都在一个正方形内，否则算失败。你可以点击右边的黑色方块选关和重玩。
According to the task requirement, click to delete the chosen pencil in order to form a required square. There are 16 tasks in all. Solve them as correctly & quickly as possible. You can click the black button on the right to choose different task and replay.