2CxHy+$\frac{4x+y}{2}$ O2-->2xCO2+yH2O
$2C_xH_y+(\dfrac{4x+y}{2})O_2→2xCO_2+yH_2O$
Choose the best answer.
We are looking for ____ place to spend ____ night.
Please turn off ___ lights when you leave ___ room.
I like _____ colorful costumes of ____ ethnic minority people in Vietnam.