A:①②
B:①④
C:③④
D:②③
—Where was your mother when the rainstorm came yesterday?
—She _________ dinner in the kitchen.
设计三种制备气体的方案:①加热稀盐酸和MnO2制氯气;②用稀H2SO4和大理石制备二氧化碳;③用稀硝酸和锌粒制备氢气,不宜采用的方案有( )
The local authority is trying to __________ oversea investment by beautifying its environment.