there is nothing to do 如图 一定是不定式么

there is nothing to do 如图 一定是不定式么 there is nothing to do 不定式to do是表示目的还是什么? there is nothing to do there is nothing to do expect do There is nothing to do but___the sky答案是C there is nothing to do but to do 还是there is nothing to do bu 请问1,所有有to do的短语都是动词不定式吗?如decide to do.2,动词不定式一定是 to do形式吗? what can we do when there is nothing to do? There is nothing to do 和There is nothing to be done有什么不一样吗? there is nothing to do except waiting还是there is nothing to d do nothing but do there is nothing to do but do/doing用哪个?举例说 there is nothing to