同一产品的供应商个数应根据（）确定。
A.产品的重要程度
B.市场供应状况
C.附近供应商的数量
D.供应商的可靠程度
参考答案：A, B, D
改错。
( ) 1. How many book do you have? __________________
A B C
( ) 2. They worked very hardly. __________________
( ) 3. The ice in the north will start to becoming water. __________________
( ) 4. You mustn't is late for school. __________________
( ) 5. Standing over there, please. __________________
某物质的分子是MCO3，它的相对分子质量是100，则M的相对原子质量是______．
