下列方程有实数根的有( )
①x2+x+4=0;②x2+4x+4=0;③x2+4x﹣2=0.
A:0个
B:1个
C:2个
D:3个
计算:( 2 +1)0﹣2﹣1+ 27 ﹣6sin60°=____.
犯罪是 ()①具有严重的社会危害性 ②触犯刑法 ③并应受刑罚处罚的行为 ④做出法律所禁止的行为
- Do you like listening to Zhang Jie's songs _________ are very loud and full of energy?
- Of course! I'm his fan.