下列有关反馈调节的叙述中,错误的是 A.负反馈调节在生物群落中普遍存在,但在生物群落与无机环境之间不存在 B.当农田里蚜虫的数量增多时,七星瓢虫的数量也会增多,这样蚜虫种群数量的增长就会 受到抑制,这属于生物群落内的负反馈调节 C.负反馈调节在生态系统中普遍存在,它是生态系统自我调节能力的基础 D.甲状腺激素分泌的调节属于反馈调节
-Is Paul in the classroom?
-No.He ________ be in the classroom , because I saw him talking with our teacher in the office just now.
[ ]
A.must
B.isn’t able to
C.can’t
D.will