1 . A child’s development is dependent on many f__________ (因素，要素). (根据中英文提示填空)

2 . Many f______ (因素，要素) make the rapid social and economic development of China. (根据中英文提示填空)

3 . There are many reasons why this has been possible, but one of the main f___________(因素) has been the Chinese writing system. (根据中英文提示单词拼写)

4 . The main f__________(因素) in deciding whether or not to do so is the size of your project. （根据汉语提示单词拼写）