DropDownList控件Item集合的Count属性值是（）。

Dependent demand for an item exists when the demand for that item is unrelated to the demand for other items. 要获取用户对DropDownList对象的选中项的内容，应该使用其（）属性。 If any item is News item 5 The opportunity cost of an item is（） You are allowed one carry -on item and one personal item on most flights, and they are both subject to size restrictions. You are allowed one carry-on item and one personal item on most flights, and they are both subject to size restrictions. A debit item in the balance of payments is: The main international payment item is（） ()控件组合了TextBox控件和ListBox控件的功能。 控件组合了TextBox控件和ListBox控件的功能（） 6. This news item is about . A push operation adds an item to the top of a（　　）. item1.setEnabled（true); What is your favorite item of________? Button?是一个复合控件，子控件有下列哪个控件()。 下列哪个控件是容器控件（） 阅读以下代码,运行结果为( )。[2,3,4,5].reduce(function(total,item){return total+item;}); In News Item 1, the phrase “in a row” means ______. According to Item 3, it is the renter’s responsibility _______.