ExercisesContentsDownloadsUNIT 24: THE PASSIVE VOICE: ALL TENSESQuestion 1 / 20请完成全部题目,最后查看答案与解析GRAMMAR · B1+ Exercise 1 · Exercise 1Choose the best answer.The new chemical ___ when it exploded.Awas being testedBwas testingChad being tested保存并进入下一题 →