Could you tell us (B.how long it takes) to travel from Earth to Mars by spacecraft?
你能否告诉我乘飞船从地球到火星要多久?
宾语从句要用陈述语序,这是原则.
A疑问词不对,不是问距离.
C和D都用了疑问语序,要去掉助动词does,然后take加上s.
Could you tell us (B.how long it takes) to travel from Earth to Mars by spacecraft?
你能否告诉我乘飞船从地球到火星要多久?
宾语从句要用陈述语序,这是原则.
A疑问词不对,不是问距离.
C和D都用了疑问语序,要去掉助动词does,然后take加上s.