单选题 The grain could have been gathered in last week if the weather had been fine: but, ______, it had to be left in the fields.
【正确答案】 D
【答案解析】解析:句意是,如果天气好,粮食本来可以在上周就收割完。但是,既然天气不好,粮食就只能放在田地里了。前半句采用虚拟语气,可知与实际情况相反,后半句描述的才是实际情况。所以正确答案是D选项。