造成自然界野生动植物资源逐渐减少的主要原因是 [ ]
A．同种生物的竟争
B．天敌过多
C．外来物种入侵
D．生存环境的破坏与改变
答案：D
____________, so he didn’t come to school last week.
A．Though he was ill
B．Being ill
C．Having been ill
D．He was ill
