A:Ⅰ染色体,ⅡDNA,Ⅲ基因
B:Ⅰ内分泌腺,Ⅱ垂体,Ⅲ肝脏
C:Ⅰ心脏,Ⅱ动脉,Ⅲ静脉
D:Ⅰ肾单位,Ⅱ肾小囊,Ⅲ肾小管
When you see an English film or talk with native speakers, observe their facial expressions and g____.
(1)解方程:1x-3=3+x3-x.(2)解不等式组:x-3(x-2)≤4x5-1<0