A:4
B:3
C:5
D:2
①它是一个无理数;
②在数轴上表示它的点在原点的左侧;
③它的绝对值比2小.
China is a country that has made great ____(contribute) to mankind in history.
1−310 =____
14+15 =____
14−15 =____
38+14 =____
56−13 =____
23−29 =____