1.As is well known to us,_____a force of attraction between two objects.
A..it always exists B..there always exists
C..it always exists to be D..there always exists to be
2.Since no one else has volunteered, Shella will be ______food to the trip.
A..responsible to supply B..responsible for supplying
C..responsible person to supply C..responsible to the
3.________that our foorball team will defeat theirs.
A..It is possibly B..It is like
C..There is a good chance D..It is a good chance
4._______he climbed to the top of the tree,he found the enemy soldiers had arrived.
A..Though B..Unless C..Immediately D..Even if
5.She knew nothing about his character and personality,_______anything about what he was really like..
A..while B..until C..or D..as

1.B. 这是there be句型的一种。
2.B. be responsible for 是一种固定搭配。
3.C. There be 句型，that引导定语从句修饰chance。
4.C. Immediately 副词用作连词引导时间状语从句。
5.C. or引导并列成分。