A:更好地发展
B:全面发展
C:协调发展
D:可持续发展
实验室制取氧气时,装药品的大试管口应( )
下图是“某地地形简图”,M点位于36.5 N。冬至日,甲、乙两个中学生分别到达P和M点,测算出两点相对高度是288米,并观测到该日正午M峰顶的影子正好移至P点。图中陡崖的相对高度,最大可能为( )
Mr. Black together with two professors ____(be) to attend our school meeting tomorrow.
Susan is a top student in our class, so she never _______ an exam.