【单选题】DNA 一条链片段 5 ' ATCG3 '另一条链:
【判断题】Three kinds of verb tenses are frequently used in English news headlines: present tense, future tense and present perfect tense.
【单选题】According to the passage, the present tense in English is ______.
A.
not used to express one's readiness to do something in the immediate future
B.
used with some verbs but not with others to express future intention
C.
basically the same in English as it is in Spanish
D.
not the most difficult problem for foreign students
【简答题】如图是某种汽车尾气处理装置中发生化学反应的微观示意图,请回答下列问题: (1)画出氮原子的结构示意图______,标出氨分子中氮原子的化合价______. (2)水分子中氧元素的质量百分含量为______.(保留一位小数)
【判断题】吸光光度分析不仅适用于溶液,也适用于任何于气体和固体。( )
【判断题】The present tense does not only mean what is true now. It can also refer to events in the past and the future.()