Read the following text carefully and choose the correct answer A, B, C or D for each of the gap.

(1) ..................you are in Singapore, you can go about by taxi, by bus, or by underground. I myself prefer the underground (2) ................... it is fast, easy and cheap. There  are (3) ................. buses and taxis in Singapore and one cannot drive along the road quickly  and without many stops, especially on the Monday morning. The underground is therefore usually quicker  than taxis or buses. If you do not know Singapore very well, it is difficult (4) ...................... the bus you want. You can take a taxi, but it is (5) ..................... expensive than the underground or a bus. On the underground, you find good maps that tell you the names of the stations and show you how to get to them, so that it is easy to find your way.

If you do not know Singapore very well, it is difficult (4) ...................... the bus you want.