【单选题】To tell the truth, what you said was too ________ for us to understand.
【简答题】月球车与地球之间保持着约 384000 千米的通讯联系。 读作:
【简答题】Thank you for your letter of April 15, ______(tell)us what really happened in the US on April 10.
【单选题】5 个人站成一排照相,若甲必须站在中间,则共有( )种不同的选法.