David didn’t give up ______ he had failed in the experiment four times.

David didn’t give up ______ he had failed in the experiment four times.

#58224

while

though

since

推荐题目

_Would you like to come to my house this Sunday? _Thank you! I’d love to. _______I have to see my uncle on that day.

#58247

And

But

—Why didn’t Betty come to school yesterday?—_________ she was ill.

#58530

But

Though

Because

I won’t go to the party       I’m invited.

#58478

when

unless

after

Grace Brown __________ play tennis every day．

#58071

isn‘t

don’t

aren’t

doesn’t．

I was late for class yesterday __________ there was something wrong with my bike．

#56675

when

that

because　　　　

until