题目

生物多样性面临的威胁主要体现为． 答案：物种灭绝的速度加快．句型转换（每空一词）。    1. I read English books once a week.（改为一般疑问句）            you        English books once a week?    2. She often eats fruit and vegetables.（对画线部分提问）                         does she         fruit and vegetables?    3. He sometimes goes skateboarding with his friends.（对画线部分提问）              does he sometimes            with his friends?    4. He went to the mountains last weekend.（用sometimes代替last weekend并改写句子）    He sometimes           to the mountains.    5. Jean often has milk for breakfast. (用now代替often并改写句子）    Jean                        milk for breakfast now.