41. She said (that) she hadn't been to the Giong Festival. (câu gián tiếp nên lùi thì, QKĐ→QKHT)

42. An experiment is being done (by them). (bị động HTTD)

43. Hoa asked me how long I had stayed there (vì ko có tân ngữ nên mình thêm me vào nhé)

44. My brother is not strong enough to lift the box.(tobe+not+adj+enough: không đủ... để làm gì ..)

45. He gets used to living near the factory. (get used to+ V-ing: đang dần quen với việc gì đó)

46. Huy doesn't run faster than Nam.(run faster><doesn't run faster)

47. I got up early so as to review the lessons. (so as to+Vo: để mà..)

48. She spent forty minutes to get there by car. (spent+time+to+Vo: dành thời gian cho việc gì)

49.  It is known that discoveries are being made by scientists.(câu bị động HTTD)

50. Did they clean the room carefully yesterday? (câu chủ động QKĐ)

$\text{Đáp án:}$

$\text{41. She said she hadn't been to the Giong Festival. }$

$\text{42. An experiment is being done }$

$\text{43. Hoa asked me how long I had stayed there.}$

$\text{44. My brother is not strong enough to lift the box.}$

$\text{45. He gets used to living near the factory. }$

$\text{46. Huy doesn't run faster than Nam.}$

$\text{47. I got up early so as to review the lessons. }$

$\text{48. She spent forty minutes to get there by car.}$

$\text{49. It is known that discoveries are being made by scientists.}$

$\text{50. Did they clean the room carefully yesterday ? }$

$\text{Cho mình xin câu trả lời hay nhất nha!}$