【多选题】Which of the following statements about open questions and closed questions is/are true?
Open questions, also called open-ended questions, are questions which have no predetermined answers.
Closed questions, also called close-ended questions, provide respondents with a set of fixed alternatives to choose from.
Respondents of closed questions are encouraged to answer the questions in their own way.
Open questions are also called fixed-alternative questions.
【判断题】今天是2019年23日10月。jīn tiān shì 2019nián 23rì 10yuè 。
【简答题】液压控制阀按其用途可分为压力控制阀 、流量控制阀 和（ ）控制阀 三大类，
【判断题】Saint Paul Cathedral is a good example of Baroque style architecture._____