一、根据汉语提示填写单词。
1. （化学）is an interesting subject, and we can learn many useful things from it.
2. I don't have enough （现金）with me, so I will pay by mobile phone.
3. A lot of young （夫妻）would like to take photos in the park on weekends.
4. It is very （便利的）for people to take the subway to go to work every day.
5. My father played （国际象棋）with me yesterday evening.

1. Chemistry
2. cash
3. couples
4. convenient
5. chess

1. 表示“化学”的英文单词是Chemistry，它是学科类名词，在句中作主语，首字母需大写，符合语境。
2. 表示“现金”的英文单词是cash，它是不可数名词，enough后可直接接该词，符合“身上没带足够现金”的句意。
3. 表示“夫妻”的英文单词是couple，空前有a lot of（许多）修饰，需要使用复数形式couples。
4. 表示“便利的”的英文单词是convenient，是形容词，符合固定结构"It is + 形容词 + for sb. to do sth."的用法要求。
5. 表示“国际象棋”的英文单词是chess，固定搭配play chess意为“下国际象棋”，符合句子语境。

二、用括号内所给单词的正确形式填空。
1. My brother enjoys collecting old ( coin ) from different countries as a hobby.
2. The school sports meeting was ( cancel ) because of the heavy rain yesterday.
3. He has a large ( collect ) of shells, and he likes showing them to his friends.
4. As ( citizen ), we should try our best to protect our city and keep it clean and beautiful.
5. He ( click ) the mouse many times, but the computer still didn’t work.
6. Research has found that regular exercise is closely ( connect ) to keeping a happy mood.
7. The government is taking measures to protect the ( coast ) environment and prevent soil pollution.
8. The rain ( continue ) to fall, so we have to stay at home.
9. In some ( case ), people had to wait for several days for the package to arrive.
10. They all have their own ( character ) hobbies and habits.

1. coins 2. canceled/cancelled 3. collection 4. citizens 5. clicked 6. connected 7. coastal 8. continues 9. cases 10. characteristic

1. 句意为“我的弟弟喜欢收集来自不同国家的旧硬币作为爱好”，different countries说明收集的硬币不止一枚，可数名词coin要变为复数形式coins。
2. 句意为“昨天校运动会因为大雨被取消了”，此处是一般过去时的被动语态，结构为was/were+过去分词，cancel的过去分词为canceled/cancelled。
3. 固定搭配a large collection of表示“大量的……收藏”，此处需要把动词collect变为名词collection。
4. 句意为“作为公民，我们应该尽全力保护我们的城市，让它干净又美丽”，主语是we，对应的名词citizen要变为复数citizens。
5. 后半句didn't提示句子时态为一般过去时，动词click要变为过去式clicked。
6. 固定搭配be connected to表示“与……相关”，此处需要把动词connect变为形容词化的过去分词connected。
7. 此处需要修饰名词environment，要把名词coast变为形容词coastal，意为“海岸的”。
8. 后半句have提示时态为一般现在时，主语the rain是第三人称单数，动词continue要变为continues。
9. 固定搭配in some cases表示“在某些情况下”，some后接可数名词复数，case变为cases。
10. 此处需要修饰名词hobbies and habits，要把名词character变为形容词characteristic，意为“独特的，有个性的”。