49. keep us warm使我们暖和

48. two weeks ago两周以前

47. take a long bus ride to乘长途汽车去、、、

46. as a special gift作为一特别的礼物

45. swim in the swimming pool在游泳池里游泳

44. a family of mice一个老鼠家族

43. lose things丢东西

42. many visitors许多游客

41. tell sb.about sth告诉某人关于某事

40. all/different kinds of butterflies各种蝴蝶