1. public class X （ 2. public object m （） { 3. object o = new float （3.14F）； 4. object [] oa = new object [1]； 5. oa[0]= o； 6. o = null； 7. return oa[0]； 8. } 9. } When is the float object created in line 3， eligible for garbage collection？（） [" Just after line 5"," Just after line 6"," Just after line 7 （that is， as the method returns）"," Never in this method."]
结构构件在荷载作用下不会发生破坏，这就要求构件具有足够的（）。 ["刚度","稳定","强度","平衡"]
体育锻炼有助于学前儿童认知能力的发展。
正常直方图，其形状特征有（）。 ["两边低","中间低","中间高","成对称","两边高"]
用户在一天内分别从A、B、C浏览器进入网站三次，百度统计统计的访客是？（） ["1","3","6","9"]
简述传感器分类。
