当前，人类与环境产生了深深的矛盾，下列做法不可以缓和矛盾的是[ ]
A．控制人口数量
B．乱砍滥伐、过度放牧
C．节能减排
D．退耕还林
答案：B
某化合物的化学式是H2nRO2n+1，其式量是M，则R的相对原子质量是______．
单词拼写
小题1:The w______ report says there will be a strong wind today.
小题2:The t_______ will stay above zero in the daytime.
小题3:The rain will stop our school’s a_____. The students won’t be happy about it.
小题4:What good weather! I think the r____ season stops.
小题5:Will the good weather l_______ long?
