【简答题】某二元混合物,其中A为易挥发组分,液相组成xA=0.4,相应的泡点为t1,气相组成为yA=0.4,相应的组成为t2,则 A.t1=t2 B.t12 C.t1>t2 D.不能判断
【单选题】某二元混合物,其中A为易挥发组分,液相组成xA=0.6,相应的泡点为t1,与之相平衡的气相组成yA=0.7,相应的为t2,则________。
【判断题】 machines allow work to be done in an easier way
【简答题】Today, bicycles are elegantly machines that are common around the world. Many people ride bicycles for recreation, whereas others use them as a means of transportation. The first bicycle was in...
【单选题】______ machines have multiplied over the centuries, even the most up-to-date list must begin with machines.
【简答题】Inventions such as refrigerators and washing machines did much to _______ () home in the early 1900s.
【多选题】在中国金融期货交易所上市交易的股指期货品种有( )。
【多选题】在中国金融期货交易所上市交易的股指期货品种有( )。
【单选题】According to the text, machines can do the following but
A.
allow energy to be transferred from one place to another
B.
change the distance and speed of a moving object
C.
perform the task automatically