多项选择题
Why did Mr. Long Yongtu get so angry? A.He thought the US negotiator was unfriendly to him. B.He thought the US negotiator insulted the Chinese people. C.He thought the US negotiator questioned the quality of Chinese pork. D.He thought the US negotiator rejected the agreement in a rude way.
单项选择题 在进行具有火灾爆炸危险的实验时引发火灾，属于生产操作不慎引发的火灾。 A、正确 B、错误
单项选择题 3．下述食品污染物中，（ ）属于食品的杂物污染 A. 131碘 B. 铅 C. 铁屑 D. 有机磷农药
单项选择题 砌体材料中块体的表示符号为？ A、M B、MU C、Mb D、Mc E、Me
