Tony is the only one of the students who _____ to europe.
A have been B has been
Tony is the only one of the students who _____ to europe.
A have been B has been
选 B has been
one of ...后面跟单数
B has been
做这类提可以把中间拿掉就容易看清楚了
Tony has been to europe。
B has been
主语三单,要用has been
Tony is the only one of the students who __B___ to europe.
A have been B has been