我拿了10年有效美国签证，是B1⼀B2，里面有一项“R”类型，是否可以多次往返？

美国十年签证，B1/B2签证页面里面的B1/B2前面的“R”不是多次的意思，每个签证页面都有这个“R”
美国签证页面里面Entries下面的M 是多次入境的意思。

Validity periods per country are listed in the U.S. Department of StateVisa Reciprocity Tables
and vary from 3 months for Iran, 1 year for China, 3 years for Russia,
and 5 years for Australia, to 10 years for Argentina, Brazil, Canada,
India, Israel, Japan, Malaysia, Mexico, Singapore, South Africa and most
European Countries.

Periods of stay for B-1 visas may be granted initially for a duration
long enough to allow the visitor to conduct their business, up to a
maximum of 6 months, and can be extended for another 6 months;[5] B-1 visas usually granted for three months or less, while B-2 visas are generally granted for six months.

是这样的！