in 时间段表示一段时间之后还是表示一段时间之内
in+ some time express some time later or within some time? 表示一段时间之后还是一段时间之内
for exampal: The plane takes off in 10 minutes. He learned to drive in three weeks. He will arrive in Beijing in 3 daysin + some time = in + some time's time = some time later ??