Over the past twenty years, American country music become    1.  

more and more popular. Some writers are no longer writing about    2.  

modern values of the USA. In 1950s, American music was about other3.  

things . Money was also thought to be important. Ten years late,     4.   

some writers turned other subjects. During these years, many young  5.  

students were angry with society. So songs were often full of angry.  6.  

Political leaders were not well thought and those songs often made   7.  

fun of them. Country music today remains much the same as ago.    8.  

One subject which country music often returns is “the good old days”.9.  

And in “the good old days”, people love life on the open air.        10.  

如图所示种群在理想环境中呈“J”型增长，在有环境阻力条件下呈“S”型增长。下列有关种群数量增长曲线及其应用的叙述中正确的是

A．当种群数量达到e点后，增长率为0

B．种群增长过程中出现环境阻力是在d点之后

C．防治蝗灾应在害虫数量达到c点时进行

D．渔业捕捞后需控制剩余量在b点