题干
There is an interval of ten minutes between the two classes，________we can have a rest.
A：when
B：where
C：what
D：which
答案(点此获取答案解析）
A
There is an interval of ten minutes between the two classes，________we can have a rest.
A：when
B：where
C：what
D：which
是某原子的结构示意图，下列关于该原子的描述正确的是（ ）
O2+HbCO ，37 ℃时，该反应的平衡常数K="220" 。HbCO的浓度达到HbO2浓度的0.02倍，会使人智力受损。据此，下列结论错误的是 ( )