—________. I saw many old things in the museum.
A:Not really
B:Of course
C:Sounds good
D:Sorry
Teachers and students make regular ____ (捐赠) to the students in need.
____
①钛合金②石墨③乙酸④稀有气体⑤硝酸钾
澳门被誉为“东方赌城”、“海上花园”,其主要经济支柱是( )