一氧化碳与空气混合的爆炸极限是12.5%-74%,指的是一氧化碳含量小于()%时,不会发生爆炸。
A、12.5
B、30
C、50
D、74
参考答案:A
— It was 3 o'clock _______we arrived at the village.
— Oh, it was also at 3 o'clock ______we arrived at the village.
[ ]
A. when; when
B. that; when
C. that; that
D. when; that
大学生为了获取技能证书而学习,这种学习动机属于()。
A.认知内驱力
B.附属内驱力
C.交往内驱力
D.自我提高内驱力