—Look! That man looks like Mr Brown.
—It __________ be him, for he _________ America.
A:can't; has been to
B:may not; has gone
C:mustn't; has been to
D:can't; has gone to
“吃动物怕激素,吃植物怕毒素,喝饮料怕色素,能吃什么心中没数。”假奶粉,地沟油,瘦肉精的出现,加剧了人们对目前食品安全的担心。为解决这种担心( )
①国家应严厉打击各种制售假冒伪劣行为
②经营者要诚信经营,自觉承担社会责任
③消费者要增强法律意识和自我保护意识
④新闻媒体要加强监督,加大执法的力度
请回答下面几个问题:
实验室制取氧气时,必不可少的最简单的一组仪器是( )