单选题
It was when I threw the dead match on the ground______I noticed something bright red trickling from under the call box door.
【正确答案】
B
【答案解析】解析：句意：就在我把燃过的火柴扔到地上时，我发现从电话亭门下流出明亮的红色的东西。本句考查强调句型。“It was+被强调部分+that+句子其他部分”，强调的对象是when I threw the dead match onthe ground。