题目

（1） 甲图中所示的实验现象说明；乒乓球在实验中的作用是 （2） 如图乙所示，敲击右边音叉，左边完全相同的音叉把泡沫塑料球弹起，这个实验现象说明声音可以传递。 答案：【1】声音是由振动产生的【2】将微小振动放大 【1】能量37、We have two new students in our school. They are Mike and Tim. They look the same, but they are not twins（双胞胎）. Mike is American. He is twelve. He is in Class Four, Grade One. He has a little sister. He often（常常）looks after her. Tim is Canadian（加拿大人）. He is twelve, too. He is in Class One, Grade One. He likes football. He often plays football with us. Mike and Tim are good friends. They are in No. 10 Middle School. （   ） 1. Mike is _______.   A. Japanese          B. Chinese       C. Canadian             D. American （   ） 2. Mike often _____ his sister.    A. looks like          B. looks after      C. looks at               D. looks the same （   ） 3. Mike and Tim are in _____. A. the same（相同的） class           B. the same school C. different grades                    D. different schools （   ） 4. Who likes football? A. Tim.             B. Mike.            C. Tim and Mike.     D. No one. （   ） 5. Which is right?  A. Mike is thirteen.                       B. Tim often looks after his little sister. C. Mike and Tim are good friends.        D. Mike and Tim are twins.