7.(★★★★★)After the war,a new school building was put up________ there has once been a theatre.

　　 A.that B.where C.what D.who

6.(★★★★)The reason________ their failure you know is________ they didn’t get fully prepared for the experiment. (福州毕业班质检题)

　　 A.why;that B.that;why C.for;that D.why;because

5.(★★★★★)-My foot hurts terribly,doctor.

　　 -Well,I wonder________ it has been like this.

　　 A.since when B.since then C.how D.when

4.The WTO cannot live up to its name________ it does not include a country that is home to one fifth of mankind.

　　 A.as long as B.while C.if D.even though

3.(★★★★★)It is at least three years________ they left here.

　　 A.when B.before C.since D.that

2.(★★★★)The thought________ he might fail in the exam worried him.

　　 A.when B.which C.what D.that

1.(★★★★)________ the new plan can be carried out will be discussed at the meeting tomorrow.

　　 A.Which B.What C.That D.Whether

31.(4分)在研究“电磁铁的磁性强弱跟什么因素有关”时，小华和小杰从实验室选取了匝数分别为50匝和100匝的外形相同的电磁铁，并先后将这两个电磁铁接入电路中，如图所示.闭合开关S后用电磁铁吸引大头针，并移动滑动变阻器的滑片P重复了多次实验，记录如下：

　(1)实验中，可通过观察____来判定电磁铁的磁性强弱.

　(2)分析第1、4次和2、5次的实验可得出结论：在____相同的情况下，线圈的匝数越____磁性越强.

　(3)分析第4、5、6次的实验记录，可得出结论：____.

30.(9分)在测定额定电压为“2.5V”小灯泡电功率的实验中：

　(1)完成实物图的连接

　(2)开关闭合前，将变阻器的阻值调到最大是为了____.

　(3)检查电路连接无误后，闭合开关发现灯泡不亮，电压表有示数，电流表无示数，造成这种故障的原因是____.

　(4)排除故障后，得到如下实验数据，请根据数据完成实验表格：

　(5)测完功率后又算出小灯泡在不同电压下的电阻值，发现电压升高时电压____(选填“变大”、“变小”或“不变”)，其主要原因是____.

29.(6分)如图所示，石块的质量为____g，在乙图中石块受到的浮力为____N，在丙图中弹簧测力计的示数为____N，石块的体积为____cm³，密度为____g/cm³，如果按图乙甲的顺序测量石块的密度，结果会____(选填“偏大”、“偏小”或“无影响”).(g取10N/kg)