Carbon dioxide is one of the primary greenhouse gases that cause global warming.

5. a / dangerous / the / place / is / city

4. books / he / interesting / reads

3. baby / happy / my / a / is / daughter

2. a / is / country / rich / Singapore

Unscramble the words to make sentences.

1. boring / Jean / person / is / a

Complete the description of Brian Skerry with the words in the box.

The man in the photo is Brian Skerry. He is from the United States. He is a photographer (1) a National Geographic Explorer. He takes pictures of sperm whales. His job is (2) but (3). That's why he loves it. He works with scientists, (4) he isn't a scientist. He takes photos to help scientists research and learn about sperm whales.

Read the text and write T for True or F for False

Even on a long trip, you don't need a lot of heavy suitcases. You only need two bags-a carry-on bag and a check-in bag. Here is some advice for packing them.

Carry-on bag

• Your carry-on bag should be small and light.

• The most important things for your trip (passport, boarding pass, airline tickets, money, credit cards, cell phone, keys, etc.) should go in your carry-on bag.

• You should pack valuable things, such as a laptop or jewelry, in your carry-on bag.

You should bring a change of clothes in case your luggage is delayed.

• You should also take any medicine you need in your carry-on bag.

• Bring snacks to eat on the plane. Cookies, nuts. and dried fruit are good. Don't bring chocolate-it's very messy. For long trips, bring a sandwich.

And don't bring water--you can't take it through security. You should buy some at the airport before you board the plane.

• Remember to bring a good book or your tablet.

Check-in bag

• Your check-in bag should be strong.

• Your clothes, shoes, and other everyday things should go in your check-in bag.

• Make a list to help you remember everything.

• Pack your bag early-don't pack on the same day as your trip!

• Think about the weather. Do you need a coat and gloves, or T-shirts and shorts? Choose the right clothes! You should pack your clothes inside plastic bags.

• Put your name and your hotel's address and telephone number on your bag. You should put this information inside the bag, too.