全部で50問 挑戦中

章なし

問題

( A )と( B )に入れるのに最も適当な組合せを選べ。

Wood ( A ) be used as the main fuel,but nowadays fossil fuels ( B ) widely.
  • (1)

    • A:used to B:are used

    • A:used to B:have been used

    • A:was used to B:are used

    • A:was used to B:have been used