题目

根据短文内容及括号内所给单词的提示填空Ken is my friend. He     (come) from London, UK. Five years ago I    (meet) him at Lily's party. Then we     (become) good friends. Ken and I     (reach) Washington D.C. at the same time. We    (start) to study medicine in the same school. Now we are still studying together. So I know more about him. Ken is funny He often     (make) up some interesting stories to make me laugh. He says he's not going to be a doctor when he graduates (毕业). He &#x（1）含相同氧原子数的O2和O3的物质的量比 ，质量之比是 ．（2）有36克CO和CO2的混合气体在标准状况下体积为22.4L，则混合气体中CO的物质的量为 ，（3）把VmL b mol/L的硫酸溶液；加水到体积为5VmL，则稀释后硫酸的物质的量浓度为 ．（4）1L K2SO4和MgSO4的混合溶液中，含Mg2+ 2.4g，SO 2-4的物质的量浓度为1mol/L，则K2SO4的物质的量浓度是 ．