24. Hanh can‘t go out tonight, she will have to (look for/look up/look at/look after) her younger sister.

25. If you want to save money, you should (reduce/recycle/repair/increase) the amount of water your  families use.

26. If we (turn on/turn off/go to/go on) littering, the environment will be polluted.

27. When Lan heard that she failed the English test, she sighed (happy/happily/unhappy/unhappily)

28. What can we do to spend less ( on / in/ about / of ) lighting?

29. Can you turn ( on / off / in / for ) the light? It‘s too dark.

30. I suggest ( take/ taking/ to take/ took) shower.

31. She failed her final exam ( so/ but/ and/ because) she didn‘t work hard.

32. You should ( turn on/ turn off/ turn up/ turn down) the lights before leaving the house.

33. In order to save electricity, an ordinary 100-watt light bulb can be replaced by ( a 1000-watt light  / a lamp / an electric bulb / an energy-saving bulb )

34. Who is going to ( look for / look up / look after/ look out ) your children when you‘re at work?

35. Scientists are looking for an (effect / effecting / effective / effectively ) way to reduce energy  consumption.

36. Passover is a festival which ( occurs / celebrates / holds / organizes) in late March or early April.

37.Tet is a time for families to clean and ( build / construct / decorate / set up ) their homes .