扩张型心肌病的主要表现是（）
A.心尖部收缩期杂音
B.心脏扩大，搏动弥漫性减弱
C.第三心音或第四心音
D.心音减弱
E.下肢水肿
参考答案：B
一个平置的双金属片，如果上面膨胀系数大，下面膨胀系数小，温度升高时，如何变化（）。
A、向上弯曲
B、向下弯曲
C、延长
D、不变化
用be 动词的适当形式完成句子。
1.There ____ ( be) a great number of books in the shelves.
2. The number of guests invited ____ (be) 50, but a number of them ____ (be)absent for the heavy rain.
3. Quantities of water ____ (be) polluted now.
4. A great deal of oil ____ (be)poured into the sea and did great harm to creatures in the water.
5. Many a famous writer ____ ( be) an alumnus ( 撰搞人) of a local newspaper.
