At first, the speaker was referring to
the problem of pollution in the country, but halfway in her speech, she suddenly _________ to another subject.
A) committed B) switched
C) favored D) transmitted
the problem of pollution in the country, but halfway in her speech, she suddenly _________ to another subject.
A) committed B) switched
C) favored D) transmitted
A.her first real success did not come until
B.her first real success came until
C.it was not until her first success came
D.it was until her first success came
A.The boy in red shorts is the first
B.The boy on red shorts is the first
C.The boy to red shorts is the first
It was the first time that such a had to be taken at a British nuclear power station.
A) presentation B) preparation C) prediction D) precaution
设有产生式:A→a|β|γ,且α、β、γ
ε。则在自上而下语法分析中,对A推导不带回溯的条件是_______。
A.FIRST(a)N FIRST(8)N FIRST(y)=Ф
B.FIRST(a)N FIRST(β)=Ф与FIRST(β)∩FIRST(y)=Ф与FIRST(a)∩FIRST(y)=Ф
C.FIRST(a)∪FIRST(8)∪FIRST(y)=Ф
D.FIRST(a)∩FIRST(β)=Ф或FIRST(β)∩FIRST(y)=Ф或FIRST(a)∪FIRST(y)=Ф
A.on
B. in
C. at
D. for
A.soup
B.sweet
C.vegetable