— How long_____like this?  

— Three weeks! It's usual in here that rain_____without stopping these days of the year.  [ ]

A. has it rained; pours      

B. is it raining; is pouring  

C. has it been raining; pours  

D. does it rain; pours

（1）在标准状况下，有物质①4gH₂，②33.6LCH₄，③1molH₂O，④3.01×10²³个O₂，含分子数最多的是（填序号，下同）______，含原子数最少的是______，质量最大的是______，体积最小的______．

（2）含有相同氧原子数的CO和CO₂，其质量比为______；物质的量比为______；碳原子数比为______；原子数比为______．