4 . According to the Beijing 2022 Organizing Committee, more than 1 million people applied to serve as volunteers and nearly 20，000 were selected, most of ________ are from colleges and universities in Beijing and Hebei Province. (用适当的词填空)

6 . Moreover, the majority are mainly the post-80s youth and 90s youth，________ don’t want to visit crowded tourist sites. (用适当的词填空)

7 . The Chinese painting brush is mostly made of goat, wolf or fox hair, ________ is suitable for producing brushes that are both soft and stringy (有韧性). (用适当的词填空)

8 . A national territorial (领土的) planning system will be guided by three “red lines”, one of ________ will include about 103 million hectares of permanent farmland. (用适当的词填空)

9 . Shaanxi’s biang biang noodles were a comforting and beloved food among locals, for ________ the back story and written character were common knowledge. (用适当的词填空)