a) You needn’t join the meeting on friday but you can if you like(d)
b) Could you read this text for me so that I can type it quickly? (c)
c) We should discuss all the major points now because we wont be able to meet again until next Sunday. (d)
d) She couldn’t drive well when she first got her driving license but she must have learnt it by now(c)
e)I think we will have to leave very early tomorrow or else we may miss our flight. (b)