骆家辉前往北京递交国书后，将正式成为美国驻华大使。
The envoy will formally become ambassador after presenting his credentials in Beijing .
他以大使身份向总统递交国书。
He presented his credentials to the President in his character as ambassador .
大使向总统递交了国书。
The ambassador presented his credentials to the president .
递交国书递交国书递交国书