–David, is that _____ English teacher?
--Yes, he is ___. He is very caring.
A:yours; ours
B:your; our
C:yours; our
D:your; ours
① ____;②____;③____;④____.
过⊙O内一点M的最长弦为10cm,最短弦长为8cm,则OM的长为( )
如图为某一人体细胞内的染色体图谱,下列叙述不正确的是( )
下列金属活动性最强的是( )
标有“220V 11W”字样的节能灯正常工作时,两端电压为 ____ 伏,通过的电流为 ____安,10小时耗电 ____ 度.