文法E—>E+EE*Ei的句子i*i+i*i有()棵不同的语法树。
A.1
B.3
C.5
D.7
参考答案:C
--- When will Han Han’s new book ________?
--- Sorry, I don’t know. I’m looking forward to his new book, too.
A.come on
B.come out
C.come in
D.come over
精馏段操作线方程y=0.75x+0.3是( )。
A.不可能的