搜题请搜索小程序“爱下问搜题”
问题 不定项选择

将力F分解成F1、F2两个分力，如果已知F1的大小和F2与F之间的夹角α，α为锐角，如图所示，则

[ ]

A．当F1>Fsinα时，一定有两组解

B．当F>F1>Fsinα时，有两组解

C．当F1=Fsinα时，有唯一解

D．当F1＜Fsinα时，无解

答案

BCD

改错题

Last Tuesday，the Students’ Union in our school advised that Senior Three students shall do something specially for their parents on their 18th birthdays. All the students are active in responding it and most of them have come up with their ideas．Some choose to write a letter saying it’s best way to express their appreciations as well as love for their parents. Others will prefer to cook a big meal to show that they have already grown up. As for me, I want to do up hair and wash feet for my parents. By doing which my parents have been doing for me I can really know how much they have devoted to bring me up. Being 18 years old mean that we should learn to be independent and that we should be responsible for us.
查看答案
单项选择题

一个Java源程序中允许有 ______ 个公共类。 ( )

A．1

B．8

C．16

D．多
查看答案