学校图书室准备买5套精装《西游记》，每套286元．一共需要多少钱？
286×5=1430（元）．
答：一共需要1430元钱．
With _______ successful launch of Tiangong-1, which was _______ breakthrough in this
field, China's space dream took a step closer to reality.[ ]
A. the; a
B. a; /
C. a; the
D. the; /,
观察的技巧主要是细心、全面和（）
A.机敏
B.敏锐
C.灵活
D.反馈
E.注视
