72．这是一个突破。

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71．只要你招招手，马上就会有出租车开过来。

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70. Distance surgery will become common as doctors carry out operations from thousands of miles away, with each city having its own telesurgery outpatient clinic.

69. The tubes were attached to a long stick which helped keep the rocket moving in a straight direction.

68. They say that the low-temperature lake is unlikely to be able to support such large living creatures.

67. Like other animals, we are on guard until we know it is safe to relax.

66. Tricycles are worth using if you want to explore the narrow alleys (hutong) of old Beijing.

65. The story goes that a ____________ animal lives in the mountain.

64. Senior citizens and people with ____________ will be able to go anywhere in the world using high-tech cameras attached to their head.

63. Just then a white-haired old woman entered,　 ____________ by a girl.