Finished but don't understand following two clues. 4d. e.g. kangaroo bar higher in all lorries at the front = Marsupial (e.g. kangaroo) but what's bar and lorries got to do with it?
25a. Miss ice shattering due to earthquake = Spasmic . Please explain.
Seismic makes sense. I must have 21d wrong as I've got A for the third letter of 25a. Just noticed I've misspelled Nairobi ( Had a and i wrong way!)
Many thanks to you both for Marsupial explanation.