如果受测者样本具有代表性，对于中等难度的测验，其测验总分应该接近（）分布。
A.正偏态
B.负偏态
C.峰态
D.常态
参考答案：D
What the public is about is whether medical workers and scientists will be able to find a cure for the new disease in a short time.
A．concerning
B．concern
C．concerned
D．to concern
（）首次提出了物联网的雏形
