1. she was so busy that she couldn't answer the phone
A. because she was very busy, she couldn't answer the phone
B. because she was very busy, she could answer the phone
C. though she was very busy, she couldn't answer the phone
D. though she was very busy, she couldt answer the phone
2.no matter how hard l tried couldn't open the door
A.although l tried very hard, l couldn't open the door
B. although l tried very hard, l could open the door
C In spite of l tried very hard, l couldn't open the door 
D, l couldn't open the door, even thouhj trying very hard
3, despite feeling cold, but we kept walking
A. although we felt cold, but we kept walking
B. although we felt cold we kept walking
​C. however cold we felt but we kept walking
D. however we felt cold, we kept walking
4. the children laughed a lot bacause of the funny story
A, the children laughed because the story is funny
B the children laughed because of the story funny
C the children laughed because it was funny
D. the children laughed because the story was funny
5, although he took a taxi, bill still arrived late for the concert
A. bill arrived late for the concert bacause he takes a taxi
B. bill arrived late for the concert bacause of the taxi
C. in spite of taking a taxi, bill arrived late for the concert
D. although bill took a taxi he can't come to the concert on time