We should bear in mind that social development and balance of nature should go in .A. comp

问题补充：

We should bear in mind that social development and balance of nature should go in .

A. company

B. sympathy

C. association

D. harmony

答案：

A. company

B. sympathy

C. association

(答案→)D. harmony

解析：四个选项分别表示伙伴、同情、联想和和睦，根据题意选D，我们应该牢记社会发展和自然平衡应该协调发展。