...们在圣诞节时交换礼物。若交换的对象为不可数名词,则只能用单数。如:The
meetings provided an opportunity to exchange information. 这些会议提供了交流信息的机会。偶尔也接单数可数名词,但比较少见。如:Trevor and I exchanged a
glance. 特...
...e 2, showed a BSFC penalty of about 1.8% per 10 kPa back pressure increase when back pressure exceeded the back pressure limit for this engine.这里的per是不是就相当于 for every? 这句话证明per后面也可以跟不是“每一”的情况?谢谢老师!
When she was that little girl in Pennsylvania,Rachel Carson never would have believed that years later she would write a scientific book that would stir up so much controversy. never的位置可以在情态动词前吗?这样是强调的用法吗? 在情态动词后是不是也可以...
... had a united command.“neither… nor…”用于连接两个性质相同的词或短语。但是在这个句子中“were neither united nor had …”可以这样用吗?同样的有一句话:Well over 90 percent of U.S. households are either wired for high-speed broadband or can get high-spe...