从上午8时到下午4时,中间经过4小时。[ ]
错误
ⅣMultiple choice.
1Fishermen and sailors sometimes claim____ monsters in the sea.
A seeing B to have seen C having seen D to see
下列方程中没有实数根的是( )
A.x2+15x+8=0
B.x2-12x+10=0
C.x2-x+1=0
D.x2+7x-5=0