An explosion is a sudden increase in amount __________.
A、 rapid burning causes it
B、 to be caused by rapid burning
C、 causing its burning to be rapid
D、 caused by rapid burning
出自:石家庄铁道大学大学英语II

完成拼图验证

按住下方滑块,将拼图拖到缺口处后松开。

拼图背景,将小拼图拖到缺口处
向右拖动滑块