题目

根据下图回答问题。(1)实验室制取二氧化碳，选用的发生装置是________(填序号)。 (2)用装置B制氧气，其反应的化学方程式是________ (3)用装置D收集氧气时，下列实验操作正确的是________(填序号)。a．加热前，将集气瓶装满水，用玻璃片盖住瓶口，倒立在盛水的水槽中b．加热后，观察到水中导管口开始有气泡时，立即收集气体c．待集气瓶里的水排完后，在水面下用玻璃片盖住瓶口，移出水槽正放 在桌面上15．There is no doubt about it．The best way to learn new words is to do it unconsciously．I don't mean while you're unconscious．I mean while you are unconscious of the fact that it is sinking in．That is how I learnt the 30，000 words in my vocabulary by living in an English-speaking world，mother tongue．I just pick them up．But some of them may be misunderstood．Now，to misunderstand does not mean not to understand．To misunderstand is to understand but incorrectly．The 5% mislearnt of all the words we"know"will be the least frequently used words，as the more frequently used words are less likely to be mislearnt．Some of the misunderstanding may live with all our lives，without knowing that we got them wrong．Many English teachers think that this natural method of learning words in one's own mother tongue can be used for a second language learning．They teach their students how to play the Guessing Game．"There is no time to look up in your dictionaries all the new words you come across，"they will say．"You have to practice guessing what the word means from the context．"This method of guessing in a second language learning does not work．It may succeed in many cases，but results in hundreds or thousands of wrongly-guessed meanings of words．And what's more，there are more separate meanings than there are words themselves．Our learners'dictionaries usually have many meanings．A good dictionary is what makes self-learning possible．Don't guess!Look it up!68．It is certain that the best way to learn new words isD． A．to learn them by oneselfB．to learn by living in an English-speaking world and using them frequentlyC．to guess them from the contextD．to get more separate meanings of each word69．The underlined word"them"in Paragraph 2 refers toA． A．the 30，000 wordsB．English teachersC．misunderstood wordsD．frequently used words70．Which of the following is most likely NOT true？DA．Some of the words the writer knows must have been misunderstood．B．Most of the 30，000 words the writer learned are frequently used ones．C．How many words the writer got wrong are not known．D．All the words the writer knows were learned by reading them．71．It can be inferred thatB． A．when somebody is conscious，he or she usually can't learn new words by heart B．we must use the words as often as possible in order to master themC．it's the best way to learn new words that one should only guess their meanings from the contextD．only dictionaries can help us learn language well．