We are all told to take part in the dish—eating up Campaign . So everyone should _____ the dishes they ordered .
A:serve
B:empty
C:catch
D:control
—Because Tony ________ for me there.
一种混凝土是由水泥、沙子、石子按2∶3∶5配制而成的,现在配制1920吨这种混凝土,需要水泥多少吨?