You are welcome to answer questions posted in the Ask a Teacher forum as long as your suggestions, help, and advice reflect a good understanding of the English language. If you are not a teacher, you will need to state that clearly at the top of your post. Please note, all posts are moderated by our in-house language experts, so make sure your suggestions, help, and advice house the kind of information an international language teacher would offer. If not, and your posts do not contribute to the topic in a positive way, they will be subject to deletion.
The WTO cannot live up to its name _____________ it does not include a country that is home to one fifth of mankind.
A. as long as B. while
C. if D. even though
The suggested answer is C, Why can't A?
Another problem:
_____ modeling business is by no means easy to get into, the good model will always be in demand.
A. While B. Since
C. As D. If
I don't know which is right? It seems B,C,D are all proper.
if or as long as ??? 
Linear Mode
