题目

--- How can I prepare for class, Mr. Johnson? ---         you          my web page? You can download the notes and read them ahead of time. A．Have … checked out                          B．Did … check out C．Are … checking out                D．Will … check out 答案：A4．在我国西部大开发中，实施“保护天然林”和“退耕还林还草”两项措施的首要目标是（　　）A．开展生态旅游B．发展畜牧业C．增加木材产量D．改善生态环境