an imbalance between ecological wellbeing and natural resources on the one hand and economic development on the other这个矛盾是谁和谁的矛盾呀?还有,between后面的名词可以是两个以上吗?
看《经济学人》遇到这样一个句子“The authorities are keen to be seen to be cracking down hard.”请问这个句子和“The authorities are keen to be cracking down hard.”有何区别?如果有,“to be seen”在句中作何理解?可以帮忙列举类似的用法吗?