21.ǰ|c_()
A.lСڴM
B.1/3̎
C.1/3̎
D.l1/3̎
E.f
𰸡C
22.ǰٿɴl߅x()
A.lϰ߅
B.l¼_߅
C.lϼ_߅
D.l°߅
E.ƽRl߅
𰸡D
23.A(y)ⲿһ㑪(yng)ԓϵLȞ()
A.23mm
B.0~2mm
C.3~5mm
D.5~7mm
E.
𰸡C
24.LҪ()
A.wLȵ1/21/3
B.Lȵ1/21/3
C.wLȵ2/33/4
D.Lȵ2/33/4
E._
𰸡D
25.TȫwA(y)rSۺϽǞ()
A.0㡫2
B.2㡫5
C.5㡫10
D.10㡫15
E.ۺϽǶȟoҪ
𰸡B
26.ȫwA(y)һ()
A.a--
B.a--
C.-a-
D.-a-
E.--a
𰸡C