单项选择题 青海玉树地震发生后，救援部队用直升飞机向灾区空投救灾物资。救灾物资在降落伞作用下加速下落一段距离后变为匀速下落，在匀速下落的过程中下面分析正确的是（）

判断题 The cognitive method regards students as the center of the teaching process, and the classes must center around the students’ drills.

未知题型 Brushes made from the first hair taken from a baby"s head was believed to bring good luck in the Imperial examinations.