A.I have been learning English for 10 years.
B.I learnt English for 10 years.
C.The last time I learnt English was 10 years ago.
D.I have started learning English for 10 years.

A.I have been learning English for 10 years.
B.I learnt English for 10 years.
C.The last time I learnt English was 10 years ago.
D.I have started learning English for 10 years.

A.Helen insisted on paying the money back to Linda.
B.Helen suggested paying the money back to Linda.
C.Helen promised to pay the money back to Linda.
D.Helen apologized to Linda for borrowing her money.

A.\(I = U\sqrt {{R^2} + {\omega ^2}L} .\)
B.\(I = \dfrac{U}{{R + \omega L}}.\)
C.\(I = \dfrac{U}{{\sqrt {{R^2} + {\omega ^2}{L^2}} }}.\)
D.\(I = \dfrac{{{U_0}}}{{\sqrt {{R^2} + {\omega ^2}{L^2}} }}.\)

A.\(\omega  = \dfrac{{{E_0}}}{{{\Phi _0}}}.\)
B.\(\omega  = {E_0}{\Phi _0}.\)
C.\(\omega  = \dfrac{{{\Phi _0}}}{{{E_0}}}.\)
D.\(\omega  = \dfrac{1}{{\sqrt {{\Phi _0}{E_0}} }}.\)

A.2,5cm.
B.5cm.
C.5mm.
D.0

A.\(90\,\,\Omega \).
B.\(150\,\,\Omega \).
C.\(250\,\,\Omega \).
D.\(1300\,\,\Omega \).

A.L, P, X.
B.L, P, Z.
C.M, P, Z.
D.N, Q, X.

A.0,66 m.
B.1,5 m.
C.6,6 m.
D.500 m.

A.Not only did I realize that I had forgotten to put a stamp on the letter but I posted it as well.
B.Scarcely had I posted the letter when I realized that I had forgotten to put on a stamp.
C.No sooner had I posted the letter than I forgot to put on a stamp.
D.Only before posting the letter did I realize that I had forgotten to put on a stamp.