再次欢迎英语天才您的光临！！come in~~

以下两题应该分别选哪一个呢？
1 If we fail ___ now, they will get out of control.
A these problems
B to deal with these problems
C to have dealt with these problems
D to dealing with these problems

2 Don't use words ,expressions,or phrases___only to people with knowledge of zoology.
A being known
B having been known
C to be known
D known

再次欢迎英语天才您的光临！！come in~~ 欢迎领导光临的对联 神给的愿望```欢迎大家光临``` 请问 谢谢光临欢迎再来 用英语怎么说？谢谢 自动弹出"欢迎再次光临1D.com虚拟社区"小窗口 英语高手请进，小弟恭候您的光临！！！ 如何翻译:董事长刘江携全体员工真诚欢迎您的光临 欢迎高手光临~ 欢迎高手光临 “请喝茶”，“欢迎下次光临”，“欢迎来到奥琳迪鞋业有限公司”。以上几句英语怎么讲？