In theory, the best way to learn a foreign language is the same way a baby learns to speak; ______in practice its not always feasible. A．when B．therefore C．none the less D．so long as
A. A．when B．therefore C．none B.so
【参考答案】
A 本题考查连词的用法，两个分句是平行的比较关系，所以when合适。题意为，在理论上，学一门外语的最好方式是采取......