—Is it ________ one on the chair near the door?
A:a, the, the
B:the, the, the
C:a, a, a
D:the, the, a
Mike used to be a top student, but he ______ behind since he lost himself in computer games.
丁丁有一本63页的故事书,笑笑有一本92页的故事书。谁每天看得多?多多少页?
每个生物体都有一定的结构层次,绿色开花植物体的结构层次是( )