问题

We can’t be successful _____we keep working hard.
A:.if
B:unless
C:because
D:although;
B:unless
C:because
D:although;
正确答案是:
同类题型
The students are full of energy.They are thirsty ________knowledge.
Mother asks me _________ computer games before finishing my homework.
Going on a trip into ______ space must bequite ______ exciting experience
It rained heavily in the south, _______ serious flooding in several provinces.
The house, ______walls are red, is where my grandfather used to live ten years ago