Question

After ten years abroad, he still recognized his old colleagues ________ he set foot in China．

A．immediately	B．for the first time
C．while	D．moment

Answer 1

A

從句式看這里需要連詞，B是介詞短語，D少the，A項immediately做連詞，表示“一…就…”,while做連詞，有雖然，當…時候，句意是：在國外呆了10年后，一踏上中國他就認出了老同事。選A。