兼用型猪的瘦肉率应在45%—50%。
参考答案:错
未成年人在遇到社会、学校和家庭保护出现“保护缺位”时,不能等待别人的保护,这就要求我们加强[ ]
A.逆来顺受意识
B.忍气吞声意识
C.退却逃避意识
D.自我保护意识
Professor Li, who I ____ abroad, still teaches in Peking University.
A.think went
B.think to have gone
C.thought went
D.thought had gone