已知氢的核电荷数为1,硫的核电荷数为16,氧的核电荷数为8,则在一个H2SO4分子中质子数共有 个,电子数共有 个,而一个氢分子中电子数共有 个。
50、50、2
下列各组词语中,没有错别字的一组是( )
A缜密 别出机杼 寒喧 声音宏亮 B弘扬 推心至腹 抱歉 百废具兴
C引申 文过饰非 贸然 貌合神离 D缺憾 义无返顾 通辑 耳熟能详
The teacher couldn't make himself _____ attention to because the students were so noisy. [ ]
A. to pay
B. to be paid
C. paid
D. pay