—What are you doing? —I'm the key to the door.A. finding out B. looking after C. looking for
---_____ is Maria? ----She is twelve years old.
---____ is Peter? --- He_____ fine.
—Hi, Lucy. Your skirt is very nice. —____
---_____ are they? --- They are Maria and Jane.
中华人民共和国的英文缩写是______.