题目

We all know that doing morning exercises ______. A．is good for our healthyB．are good for our healthyC．are good for our healthD．is good for our health 答案：D解析:略5月1日A.太阳直射在南半球B.南非白昼逐渐变长C.上海正午太阳高度逐日升高D.地球公转的速度逐渐加快