A:exciting
B:excited
C:excited about
D:exciting about
已知实数x,y满足1≤x+y≤3-1≤x-y≤1,则4x+2y的取值范围是____
把下列各数分别填入相应的大括号内:
−7,3.5,−3.1415,π,0,1317,0.03,-312,10,,-42
自然数集合{ …};整数集合{ …};正分数集合{ …};非正数集合{ …};有理数集合{ …}.