问题
单项选择题
力在某轴上的投影等于零，则此力与该轴（）
A、平行
B、垂直
C、成任意角
D、成45°
答案
参考答案：B
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力在某轴上的投影等于零，则此力与该轴（）
A、平行
B、垂直
C、成任意角
D、成45°
参考答案：B
| 完形填空 | ||||
| Someone once wrote, “All work and no play make Jack a dull boy.” Work is 1 but everyone needs leisure time too.Leisure time 2 free time to do whatever you want. 3 is a time for anything that 4 you. Some people like to play 5 for good health, Others like to go to interesting places, 6 museums or parks.Many people have 7 . They make things or collect things. Right now,someone is 8 a hobby somewhere.People collect coins, 9 ,rocks,or books. Everyone likes to make something. 10 could make a boat or a table,a sweater or a fishing net,a bird cage or an apple pie.It does not 11 what you make,as long as it’ something you do yourself. People 12 hobbies are not dull. They are interesting 13 they can talk about their leisure 14 . Some work and some play will make you interesting, 15 . | ||||
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