She ran 100m in an ______ 10.9 seconds.(astonish)

She ran 100m in an ______ 10.9 seconds.(astonish)
【正确答案】：astonishing
【题目解析】：本空修饰10.9 seconds，表示令人震惊的，故应该在动词astonish后加-ing。若加-ed则表示感到震惊的。答案为astonishing。