The sports meeting won't be put off _____ it rains．（ ）
A．untilB．ifC．unlessD．whether
Mary____ a math problem with her classmates when the math teacher knocked at the classroom door．（ ）
| A． |
has discussed |
B． |
was discussed |
| C． |
was discussing |
D． |
discusses |
______you practice， _________you will be at math．（ ）
| A． |
The more； the better |
| B． |
The more； the best |
| C． |
The most； the better |
| D． |
The most； the be |
Jack has learned more about teamwork（团队合作） _______ he joined the soccer team．（ ）
| A． |
until |
B． |
since |
C． |
while |
D． |
though |
_____ my friends _______ I like playing computer games because we think it wastes time．（ ）
| A． |
Both； and |
B． |
not only； but also |
| C． |
Either； or |
D． |
Neither； nor |
_________do your parents come to visit you in the US， Tom？
Once a year．（ ）
| A． |
How often |
B． |
How long |
C． |
How soon |
D． |
How far |