下列句子没有语病的一项是( )
我国婚姻法禁止近亲结婚的医学依据是( )
Don't forget____ (take) your pen because you might want to write something.
圆(x﹣1)2+y2=1和圆x2+y2+2x+4y﹣4=0的位置关系为( )