—Mary，I don’t know ____ you can come tomorrow morning.—No problem! I’ll be here ____

—Mary，I don’t know ____ you can come tomorrow morning.—No problem! I’ll be here _____I’m free then.

#55784

if；if

if; whether

whether；till

whether；until

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Remember to wash your hands __________ you have meals.

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before

until

though

unless

—Do you like playing tennis? —No， ____ I like sports．I play football every Sunday

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and

but

I work harder at my lessons this year _____ I have made good progress.

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but

and

for

 As we all know the H1N1 Flu is so serious, students can’t go into the school _______ they take the temperature and get sure they don’t have a fever.

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till

after

when

until

 I want to know          Tom can help me with my maths.

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because

although

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