可导致环境人口容量降低的因素有[ ]
A．科技水平提高
B．环境质量下降
C．资源过度使用，利用率低下
D．社会经济发展水平逐步提高
BC
“What place is it?” “Haven’t you found out we _____ back where we ______?”
A．were, had been
B．have been, are
C．are, were
D．are, had been
在D08-32型捣固车动力传动系统的主传动车轴齿轮箱中，轴承和齿轮的润滑采用的是（）方式。
A.压力润滑
B.飞溅润滑
C.飞溅和压力润滑相结合
