填空题 Questions 7-9
Choose THREE letters, A-G.
Write your answers in boxes 7-9 on your answer sheet.
Which THREE of the following seven pieces of safety equipment are suggested for use with a hot air balloon?
A．Drop line
B．Gas valve
C．Piezo ignition
D．Synthetic clothing
E．Fire-proof gloves
F．Flint spark lighter
G．Propane combustion