when
before
since
until
第1题:
A.How soon
B.How often
C.How many times
D.How long
第2题:
A.I have not done this yet.
B.Less than 6 months
C.More than 6 months but less than 1 year
D.1-2 years
E.2-3 years
F.More than 3 years
第3题:
A、to correct
B、to be corrected
C、for correcting
D、corrected
第4题:
第5题:
第6题:
How many holds do you have?
第7题:
Scientists have many theories about how the universe ___ into being.
A. cameB. was coming
C. had comeD. would come
第8题:
Many scientists have been probing psychological problems.
A.solving
B.exploring
C.settling
D.handling
第9题:
第10题: