题目

仿照例句改写下面的句子例：If I were in your position，I would pay close attention.→Were I in your position，I would pay close attention.（1）If Jack were here at this moment，he would lend us his car.→   （2）If I had remembered their address，I would have sent them some cards.→   （3）If we were not waiting for a telephone call，we would go downtown.→   （4）If they had recognized her，they would have spoken to her.→   （5）If I had been intending to go shopping，I would have let you know.→&#根据下列实验示意图回答相关问题：（1）A实验中未观察到明显现象的原因______；（2）B实验可能造成的后果______；（3）C实验测定结果偏低的原因______；（4）指出D实验中的错误______．