The forty years from the 1930s to the 1970s was an important period in the development of air transportation。 the earliest passenger flights were successfully operated。 to make travel easy and pleasant for the passengers。 to provide different services。 the shortage of qualified pilots。 traveling by air was very cheap。
Air transport companies use different planes__________. in the development of air transportation。 the earliest passenger flights were successfully operated。 to make travel easy and pleasant for the passengers。 to provide different services。 the shortage of qualified pilots。 traveling by air was very cheap。
I tried very hard to persuade him to join our groups but I met with flat refusal. disapproval。 rejection。 refusal。 decline。
The moon was obscured by thick clouds. held。 prevented。 darkened。 blackened。
She can speak French and German，let alone English. to say nothing of。 to speak nothing of。 to talk nothing of。 to tell nothing of。
The legislative provision has a great impact on the operations of the department.
