找出与所列单词意义相反的单词.
1 dull
a.severe
b.keen
c.solid
d.careful

2 obey
a.defend
b.escape
c.rejoice
d.resist

3 attack
a.defend
b.contribute
c.scatter
d.suffer

4 float
a.neglect
b.appose
c.sink
d.leap

5 smooth
a.stubborn
b.rough
c.sharp
d.cruel

答案：b d a c b