Scientists have found no ________of life on Mars so far,though great efforts have made on the research.
#7179
A
symbols
B
signs
C
marks
D
signals
推荐题目
All the indicate that he has been deeply involved in the crime.
#6454
A
evidence
B
fact
C
factors
D
cause
On Saturdays, students are very proud to be on the street to guide passers-by to obey traffic rules.
#5159
A
characters
B
volunteers
C
operators
D
graduates
In English colleges, classes are often arranged in freer and opener______and many jobs are designed for students.
#7378
A
grades
B
ranks
C
customs
D
patterns
Hardly a month goes by without ______ of another survey revealing new depths of scientific illiteracy among US citizens.
#7309
A
words
B
word
C
a word
D
the word