The most important thing_____we should pay attention to is the first thing _____I have said.

Can you tell me _______ when I called you

Mary believed it was just the license number that she had chosen ___brought her the good luck

下面文字空缺处需要加上一些虚词，下列选项中的虚词最恰当的一组是（ ）创新的行为要在脚踏实地中稳中求进。因此创新的想象可以海阔天空， ① 一旦付诸实践，就要脚踏实地、严肃认真， ② 稍有不慎，就可能带来较大损失， ③ 在战场上严重失利。创新要坚持稳中求进，要进行充分的科学论证，全面考虑各种主客观因素影响。“稳”是前提，“进”是目的。保持稳妥是为了更好地进取。 ④ 只求稳不求进，就成了“空想家”。

However, Iran _____ that its nuclear plan is only for peaceful purposes, and continues its nuclear activity. [ ]