Normally it takes about one week for an air-mail letter to reach America.
Normally it takes about one week for an air-mail letter to reach America.
通常情况下，航空邮件到达美国需要大约一个星期。
Normally it takes about one week for an air-mail letter to reach America.
通常情况下，航空邮件到达美国需要大约一个星期。