Active Voice & Passive Voice

I think they make these cars in Japan.

I think (a)   in Japan.

You must not drop litter in the street in Singapore or you'll get a fine.

(a)   in the street in Singapore.

Someone smashed our window last night.

(a)   last night.

They have already mended the TV set. You can collect it.

(a)   You can collect it.

People will need more public transport in the near future.

(a)   in the near future.

Don't enter the room. They are decorating the walls.

Don't enter the room. (a)  

You should not replace the roof at the beginning of winter.

(a)   at the beginning of winter.

People are spending less money on cars this year.

(a)   on cars this year.

They had cooked the meal before 10 o'clock.

(a)   before 10 o'clock

Someone was building the wall when I was there.

(a)   when I was there.