1.
In addition to a passport, visitors must hold valid visas issued by the American authorities prior to departure.
在去美国之前，除护照外，旅行者必须持有美国使馆签发的有效签证。
2.
entry-exist visa valid for a single journey
一次性有效出入境签证;一次有效出入境签证
3.
To certify or attest to(the validity of a signature on a document, for example)as a notary public.
公证检验或证明（如文件签字是否有效），作为公证
4.
Passport, valid at least90 days after expiration of the visa, with a photocopy of the identity page.
护照在要签发的签证有效期后需仍有九十天的有效时间。
5.
They applied for an extension to their visas.
他们申请延长签证有效期。
6.
They extended her visa.
他们延长了她签证的有效期限。
7.
Health certificates are valid for six months from the date of issuance.
健康证明书自签发之日起6个月有效。
8.
The certificate which was used to sign is unavailable, and therefore cannot be validated
签名证书不可用，因此无法验证其有效性
9.
Our offer is subject to approval of export licence.
"出口许可证准许签证,我方报价才有效. asasdfas"
10.
The signing certificate has expired or is not yet valid.
用来签名的证书已过期，或还没有到有效期限。
11.
The time draft is to be countersigned by the Bank of Hong Kong, certifying that your signature is true and valid.
远期汇票要由香港银行回签，以证明你方签字是真实、有效的。
12.
The time draft is to be countersigned by the Bank of China, Beijing, certifying that your signature is true and valid.
汇票要由北京中国银行附签，以证明你方签字是真的和有效的。
13.
Your visa is for one month. Have you got a return ticket?
你签证的有效期是一个月，您买了回程票了吗？
14.
Article 6 Foreign passport holders shall enter the ROC with a valid visa.
第6条持外国护照者，应持凭有效之签证来我国。
15.
Our certificates are made valid by means of the official seal and personal chop of the commissioner.
我们的证明书以盖公章和局长签字为有效。
16.
High efficient proxy signature scheme with designated verifier
高效的具有指定验证者的代理签名方案
17.
"When applying for various visas, aliens shall present valid passports and, if necessary, provide pertinent evidence."
外国人申请各项签证,应当提供有效护照,必要时提供有关证明。
18.
There are many types of visas: Bi--short visit for business;
签证有多种类型：BI——短期商务旅行签证；