题目内容：
（ ）I don’t know __________.
A．how often he visits his grandparents B．how soon will he come back
C．how many students are there in his class
D．how long is the bridge
参考答案：
答案解析：
单选题：（ ）I don’t know __________.
- 题目分类：英语
- 题目类型：单选题
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B．how soon will he come back
C．how many students are there in his class
D．how long is the bridge