1.Seeing is believing.
2.Playing football is great fun.
3.Typing is a hard job.
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50.Learning English is no easy job.动词+ing，也称作动名词，具有动词的特性又作名词，所以可做句子的主语。如上诸例，表示“做**事”如何如何，可想到生活中"做"的各种事情作主语组成句子。 不知道你是什么程度的，只好抛砖了。Watching TV is my favourite. Drinking alcoholis forbidden in school. Smoking is harmful to our health....