If you don't hear a dial tone, your organization or telephone might not support this type of outside call, or might require an additional access code.

如果未听到拨号音，表明您所在单位或您的电话可能不支持这种对外呼叫类型，或需要额外的访问号码。

youdao

If you don't hear a dial tone, your organization or telephone might not support this type of outside call, or might require an additional access code.

如果未听到拨号音，表明您所在单位或您的电话可能不支持这种对外呼叫类型，或需要额外的访问号码。

youdao