酸都能使紫色石蕊试液变红色是因为( ) A. 分子中都有氢原子 B. 酸溶液中都含有 C. 酸都是含氢的化合物 D. 酸都有酸根 答案:B句型转换。1. A. I want to enter the Piano Competition. B. I want to ________ ________ ________ the Piano Competition. 2. A. Christmas Day is on December 25th. B. Christmas Day is on ________ ________ ________ ________. 3. A. She was late yesterday because she was ill. B. She was late yesterday ________ ________ her illness(病). 4. He had a party at home on weekend. (改成一般疑问句) ________ he ________ a party at home on weekend?5.He sneezed for one minute. (对划线部分提问) ________ ________ ________he sneeze?