for the first time，jump out of，at the end of，around the clock，apply for，in advance，engage in，check in
（1）People who do very important jobs sometimes have to work

around the clock

around the clock

.
（2）I'd appreciate it if you could let me know

in advance

in advance

whether or not you will come.
（3）We are now

engaged in

engaged in

a great and most glorious cause，never undertaken by our forefathers.
（4）Passengers with hand luggage can go straight to the departure gate to

check in

check in

there.
（5）The minute you

apply for

apply for

insurance，carriers have the right to dig through your medical records.
（6）I don't think I'd have the courage to

jump out of

jump out of

a plane.
（7）Peter will take up his post as the head of the travel agency

at the end of

at the end of

next month.
（8）Naturally，you were nervous when you went on the platform

for the first time

for the first time

.