1.应该为Will you explain this question to us again?
explain ……to……,把……解释给某人
2,应改为It was such fine weather ……
so 后面应该加形容词,如so beautiful ,so good,如she is so beautiful that I can't help looking at her.
本句中后面是fine weather ,为名词性短语（fine 是修饰 weather,中心词还是weather）,应该用such .