While we were sleeping, it snowed! It snowed while we were sleeping! While he was cooking, a parcel arrived. A parcel arrived while he was cooking. 2 “While” 作连词时，可以表示 “但是，然而”。 One of the twins is shy ...

As of now, China's 240-hour visa-free transit policy applies to 55 countries, while nationals from 47 countries are eligible ...