【題目】All the travelers are ________ the guide for helping them.

【題目】—Mum, I'm afraid I can’t make it.

【題目】The boy ________ always thinks of others is popular with his classmates.

【題目】People often ________ forests to get more land to grow crops in the past.

【題目】I like reading very much. When I read, time goes ________.

【題目】If you feel ________ before exams, listen to some music to relax.

【題目】At the end of 2017, the second plane of C919 ________ its first test fly in Shanghai.

【題目】Knowledge will be forgotten ________ we use it.

【題目】It's everyone’s job to take action to ________ our environment.

【題目】High-speed trains made in China are ________ fast ________ safe.