题目

The new playground to be built next year will be ____________ the old one. A . as three times big as B . three times as big as C . as big as three times D . as big three times as 答案：B在“探究酸雨对种子萌发影响”的实验中，变量是（　　） A、温度B、PHC、氧气D、种子的大小