Question

Kate's dad is getting old. She will go back home to see him _____it is convenient

1. A.
   because
2. B.
   whenever
3. C.
   although
4. D.
   unless

Answer 1

B
because因为；whenever无论什么时候；although虽然，尽管；unless除非，如果不。句意：凯特的父亲老了。无论什么时候她方便，她都会回家去看他。结合语境可知选B。
考点：连词辨析