在自然界中，动植物的遗体不会永远保留着的原因是（　　）

A．动植物的遗体自身会分解

B．土壤中的小虫子可以分解

C．腐生细菌和腐生真菌，能够分解动植物遗体

D．绿色植物能够分解动植物遗体

I advised that he ______ to the hospital at once, but he insisted that he ______ quite well then.

A．was sent; felt

B．be sent; was feeling

C．he sent; feel

D．should be sent; should feel