单项选择题 As we know, blood types A and B cannot receive AB, but AB may receive A or B. Type O can give to any other group; hence it is often called the（） donor.

单项选择题 His latest piece of work was（）by a song he heard on the radio.

单项选择题 Each of them had a different（）of what actually happened, but hers was by far more believable.