A:O2的转化率提高了
B:正反应速率不变
C:18O只存在于SO3中
D:18O存在于各物质中
⑴____ A. snow B. blow CwindowD. flower
⑵____ A. down B. bowl C. brownD. town
⑶____ A. please B.sweater C.peachD. teacher
⑷____ A. find B. Give C. picnic D. sing
⑸____ A. take B. race C. last D. name