boy has never___(ride) a bicycle because he is too young
2、There were many___(invention)in the old days in china 3、The visitors ___(fly)to Kunming yesterday.4、They had fun ___(play)computer games.5、Henry Ford ___(open)a car factory in 1908.6、The earth goes round the sun.(改为一般疑问句）7、The first passenger railway opened (in 1825)(对括号内部分提问）8、He has been to London,too(改为否定局）9、My favourite type of transportation is (walking)(对划线部分提问）10、Most Americans like to be humorous(反义疑问）