-This kind of sports is exciting.-Yes, but it's dangerous. One can't do it_______ he or she has got some training.
A: if
B: after
C: when
D: unless
A: if
B: after
C: when
D: unless
举一反三
- W: Can we leave the lab now, teacherM. No, you must tidy the lab before you leave. When can the student leave(). A: The student can’t leave unless he has put everything back in the cupboard. B: The student can leave after he turns off the electricity. C: The student can leave after he has tidied the lab.
- Why can’t Helen come after class A: [A] Because she has to do cleaning. [B] Because she has to meet Bob. [C] Because she has to come home and look after her mother.
- After the staff training, the company need some ______ system to test the effects of training.
- He is sure to come_______ he has some urgent work to do at home. A: unless B: if C: though D: since
- Did Ling ling like the London Eye ?_____ A: Yes, she do B: Yes, she did C: Yes, he did D: No. he didn ’t