下面片段选自某高中英语课堂教学实录。 T: Good morning, boys and girls. We talked aboutsome verbs yesterday. Now I’d like to see whether you have learned to use them.Are you ready? Ss: Yes. T: Listen! Yesterday, you were going to playfootball after school when it began to rain, so you didn’t do it. Can youdescribe it with the word “prevent”? Who would like to have a try? S1: We didn’t play football yesterday because asudden rain prevented us. T: OK. But would you please begin your sentencewith “The sudden rain…”? Who’d like to try? S2. The sudden rain prevented us to playfootball yesterday. T: Oh, you are so quick, and you are almostright. Do we say “prevent somebody to do something” or “prevent somebody…” S3: Oh. The sudden rain prevented us fromplaying football yesterday. T: Perfect. Let’s read S3’s sentence together andremember the verb pattern of “prevent”, OK? 根据该教学片段回答下面四个问题： (1)该教师采取了什么方式引出复习巩固的内容？（5分） (2)当该教师发现学生没有完全掌握所学内容时，采取了什么补救方法？(5分 (3)这种补救方法有哪两个优点？（10分） (4)该教师复习巩固所教内容还可以采用其他哪两种方法？（10分）