1 . Astronauts usually sleep in private quarters or in sleeping bags________(attach) to the walls or the ceiling. (所给词的适当形式填空)

2 . He asked the officials _________ (concern) to put safety at the first place. (所给词的适当形式填空)

3 . I still remember the happy days ________(spend) with the students from other cities at the summer camp. （所给词的适当形式填空）

4 . The music took me through the twists and turns of a classic story about a young couple ________ by their families．(根据句意填空)

5 . Instead, you should set goals ________ (base) on your abilities and skills. (所给词的适当形式填空)