请问这怎么翻译的,thanks怎么选择Had electronic computers not been invented, many problems of space flight ______ now. A. could not have been solved B. could not be solved C. must not be solved D. should not have been solved

来源:学生作业帮助网 编辑:作业帮 时间:2024/09/10 18:28:13
xQJ@a¿Cm$9oZUoc|#\'wC