生态系统都是由生物部分和非生物部分组成,消费者是指( )
A.人类
B.所有动物
C.细菌、真菌
D.所有动物和细菌、真菌
答案:B
Tom and I went boating yesterday. _______ had a good time.
A.We
B.They
C.She
D.It
胃气上逆,可引起
A.嗳气呃逆B.头痛、头胀、面红目赤C.胃脘痛D.脘腹有重坠感