Cai Hua(2013) and Huang Xinyu(2014) discussed their opinions from different aspects。 Huang Xinhua’s ideas were based on students and Cai Hua’s ideas were based on teachers, students and environment。 Therefore, Cai Hua’s ideas were more widely。 Maybe it’s better for Huang Xinyu to talk about the differences between urban middle school English teachers and rural middle school English teachers because those teachers in these two areas have a lot of differences。 

Littlewood & Liu(2011) did two large-scale surveys conducted at the University of Hong Kong。 The surveys indicate that most students have enjoyed inadequate speaking opportunities at school, where "listening to teacher" has been their most frequent classroom experience。 Many have low confidence in their ability to speak without prior planning。 Many students feel unease when speaking English。 This unease is often reinforced by students' anxiety to speak well and some teachers' error treatment techniques or high expectation。 

Jane Jackson(2002) did an ethnographic study in Hong Kong and investigated the reticence of Chinese students in four sections of an English-medium undergraduate business course。 He found that a complex mix of affective, sociocultural, and educational factors played a significant role in determining the level of interaction。

Saville-Troike(1985) found out that Asian students’ silence in class had something related to teachers’ teaching method。 Some students are afraid that their answers are different from what teachers expect and they think teachers will blame them for this or this will leave a bad impression on teachers。 

Ferris & Tagg(1966) did an investigation about students’ participation in interaction in class and found that a lot of students were passive in participating the group discussion, asking questions or answering questions。 They were reluctant to take part in those activities。 Then he did a further investigation and concluded that the reasons of students’ silence are lack of target language proficiency and the ability to communicating with others by using the target language。 

HM InnamuUah analyzed the English classroom silence from teachers’ aspect and found that students’ silence is closely related to teachers。 If the teacher cannot tolerate, encourage, praise or adapt students’ ideas or cannot provide students with correct guidance or cannot organize class discussion or cannot use appropriate question strategies, students will keep silence in English class for a long time。

2。2。2 Domestic and foreign researches about causes of classroom silence and ways to improve students’ participation

After analyzing the causes of classroom silence, Huang Xinyu(2014) gave some suggestions to improve classroom interaction and reduce classroom silence。 

First, teachers can strengthen the comprehensible input and adapt various kinds of input methods。 Sometimes, students may have some difficulties in understanding teachers’ instructional directives。 So teachers need to pay attention to students’ language ability and use simple, clear and normative instructions。 

Second, teachers can build up a relaxing classroom atmosphere to help students overcome their anxiety。 文献综述

Third, teachers need to improve their ways of questioning and give students certain guidance and positive feedback。 

Forth, teachers need to consider the difference between rural schools and urban schools。 

Hu Qiaoqiao(2014) analyzed the causes of classroom silence under the guidance of Constructivist learning theory and effective teaching theory。 She analyzed the causes from three aspects: teachers, students and environment。 Her ideas were similar to Cai Hua’s。 Based on her own studies, she concluded that the teacher had the biggest influence on junior middle school students。 and she put forward some measures to deal with students’ classroom silence from the perspective of teachers, i。e。, to understand classroom silence correctly; to set up scientific education views; to improve teaching abilities; to build a good relationship between teachers and students and construct good class atmospheres。