A) 根据括号中所给的汉语写出单词，使句子意思完整正确。
61. Now many people in the USA prefer to live in the countryside because they think cities are too ____________ (被污染的).
62. There is no ____________ (可能性) that she will finish the task on her own.
63. My mother is very good at making ____________ (味道好的) dishes at home.
64. The workers are planting trees to ____________ (将……圈起来) the building.
65. Scientists have to ____________ (专门地) build houses for people to live on Mars.

B) 根据句子意思，用括号中所给单词的适当形式填空。
66. Walking on the Moon will be ____________ (danger) because of the gravity.
67. It ____________ (hope) that we can try another way to build a bridge for the villagers.
68. Some students said ____________ (live) on Mars would be more exciting.
69. There are so many good programmes that I can hardly make a ____________ (choose) among them.
70. Gravity can prevent us from ____________ (jump) too high in the air.

六、句型转换（共5分，每小题1分）
71. If fish don’t have enough water, they will die. (改为同义句)
Fish will die ____________ ____________ ____________.
72. I didn’t go out yesterday because it rained heavily. (改为同义句)
I didn’t go out yesterday ____________ ____________ the ____________ ____________.
73. The man is too tired. He cannot continue with the work any longer. (合并为一句)
The man is ____________ ____________ ____________ ____________ with the work any longer.
74. Neil Armstrong received his student pilot’s licence at the age of 16. (对画线部分提问)
____________ ____________ Neil Armstrong ____________ his student pilot’s licence?
75. Is there enough water or oxygen on Mars? Scientists are not sure about that. (改为宾语从句)
Scientists are not sure ____________ ____________ ____________ enough water and oxygen on Mars.