题型:选择题 Around our village there are many trees which ______ rubber (橡胶). [ ]A. make B. are made C. produce D. build 查看答案
题型:问答题 (1)在标准状况下,44.8L的NH3气体质量为______g.其中含______mol氮原子,含______个氢原子.(2)质量相等的HCl、CO2、NH3、CH4四种气体中,含有分子数目最少的是______,在相同温度和相同压强条件下,体积最大的是______,密度最小的是______. 查看答案