42. She has taught her children to play the piano for 4 years.
A. She started to teaching her children to play the piano 4 years ago.
B. She started teaching her children to play the piano for 4 years ago.
C. She started teaching her children to play the piano since 4 years.
D. She started teaching her children to play the piano 4 years ago.
43. "Why don't you use energy saving - bulbs, Nam?, said Minh.
A. Minh reminded Nam to use energy saving bulbs.
B. Minh asked Nam not to use energy saving bulbs.
CMinh suggested that Nam should use energy saving bulbs.
Minh had Nam replace energy saving bulbs.
al was very exhausted, but I didn't stop working.
il stopped working because I was exhausted.
Even though I was very exhausted, I didn't stop working.
CI didn't stop working; therefore, I was very exhausted.
D. If I didn't stop working, I would be very exhausted.
45. We don't know where we should put the sofa.
A. We don't know where putting the sofa.
B. We know where to put the sofa.
C. We don't know where should put the sofa.
D. We don't know where to put the sofa.
oir correct forms