1/为什么是Do you know how many colours there are in the rainbow?而不是Do you know how many colours are there in the rainbow?2/How many colours are there in the rainbow?是否正确?
问题描述：
1/为什么是Do you know how many colours there are in the rainbow?
而不是Do you know how many colours are there in the rainbow?
2/How many colours are there in the rainbow?是否正确?
答
句首有do you know, do you think 这类词来引导整个句子的时候，后面的句子要用陈述语序，即：主+谓+宾 的结构。
第二个句子为一般疑问句: 疑问词+谓语+主语+状语. 是正确的。
答
正确的说法应是：Do you know how many colours there are in the rainbow?
就如：你知道你自己多少岁吗？译：how old are you？或Do you konw how old you are？而不是Do you konw how old are you？因为前面多了短语“Do you konw ”，主语就变成了它，“how old you are”就是前面的宾语补足语
答
1.那是因为Do you know 后面跟的是陈述句语序.(know后面的句子充当know的宾语)
比如说 Do you know How much I love you?
Do you know what class he is in?
2.这个句子是正确的,是一个正常的疑问句.