一梁在集中力F作用下，其应变能为Ve。若将力F改为2F,其他条件不变，则其应变能为( ) A: 2Ve B: 4Ve C: 8Ve D: 16Ve

【单选题】A.f i ve B.g i ve C.d i ve D.dr i ve A. f i ve B. g i ve C. d i ve D. dr i ve

工作在放大状态的NPN型三极管，其三个电极的电位关系是（）。 A: VE>;VB,VC>;VB,VE>;VC B: VE>;VB,VC<;VB,VE>;VC C: VB>;VE,VB<;VC,VE<;VC D: VB>;VE,VB<;VC,VE>;VC

Watch the video clip again and fill in the blanks with the information you’ve got.TimBut what 1) —you’ve got so many bags?Oooh, 2) ! You’ve been 3) again?I hope you’re not 4) .Last month you told me you spent 5) on face lotion, and today you’ve bought 6) .As an old saying goes, “7) .”If you like, I could help you 8) .

TimBut what 1)—you’ve got so many bags? Oooh, 2) ! You’ve been 3) again? I hope you’re not 4). Last month you told me you spent 5) on face lotion, and today you’ve bought 6) . As an old saying goes, “7) .” If you like, I could help you 8) .

工作在饱和状态的PNP型晶体管,其三个极的电位应为 A: VE>VB，VC>VB，VE>VC B: VE>VB，VC<VB，VE>VC C: VB>VE，VB<VC，VE>VC

异交植物或动物可以用（ ）个公式来估计环境方差。 A: VE=VF1 B: VE=VP1 C: VE=VP2 D: VE=1/2(VP1+VP2)

哪些是健身运动消除疲劳的维生素? A: VA、VE、VD B: VA、VE、VB1 C: VA、VE、VC

NPN型的三极管导通过程：（）。 A: Vc>；Vb>；Ve B: Vc>；Ve>；Vb C: Ve>；Vb>；Vc

当NPN型管处于放大状态时,三个电极电位满足() A: VB＞VC＞VE B: VC＞VB＞VE C: VB＞VE＞VC D: VE＞VB＞VC