Ⅰ.用所给单词的适当形式填空
1．The ________(bake) are working happily.
2．There will be a big ________(sell) in this supermarket this weekend.
3．________(invent) make our life easier and more comfortable.
4．It is ________(danger) to climb up the tall tree.
5．The students in my school got to the museum in ________(little) than 30 minutes.
