请在航班起飞前两小时到柜台办理登机手续。

Please ___check in at the counter two hours before your flight departure.

请在登机前用手机办理值机手续。

Please ___check in on your phone before boarding the flight.

我每天都会给父母发消息报平安。

I text my parents every day to ___check in and let them know I'm safe.