题目

We _______ our grandmother’s 79th birthday the day after tomorrow.A. celebrate B. celebrated C. will celebrate D. were celebrating 答案：【答案】C【解析】句意：后天我们将庆祝我们祖母的79岁生日。A. celebrate庆祝，原形； B. celebrated庆祝，过去式； C. will celebrate将庆祝，将来时；D. were celebrating正在庆祝，过去进行时。根据时间状语the day after tomorrow.可知用一般将将来时。根据题意，故选C。用分子或原子的观点解释下列问题：①气体比固体容易被压缩：______；②空气中的氧气和实验室制取的氧气均可支持燃烧：______．