DIRECTIONS Look for the main idea in each of the following paragraphs. Remember that the main idea is the overall point of the paragraph.

1. Many people know an orca when they see one. Orcas have distinct black-and-white markings that make them easy to recognize. Commonly known as killer whales, they are a popular subject for documentaries and feature films. Frequently, orcas are featured performers in aquatic shows. Perhaps no other sea mammal is as familiar to people.

2. There are some common misconceptions about orcas. For one thing, they are not, as some people think, the largest species of whale. The orca is merely the largest member of the dolphin family of whales. Furthermore, many people think of orcas as solitary creatures, but they usually live in groups of up to fifty animals.

3. Killer whales hunt in organized groups. Working together, a group of killer whales can herd prey animals into shallow water, trapping them against the shore. Orcas’ speed and body shape are ideal for hunting. Large, strong teeth and powerful jaw muscles help them seize large prey. Although they usually feed on fish and squid, they have been known to hunt successfully animals as large as great whales.

4. Orcas were once called whale killers, but the name has somehow been transposed to killer whales. Orcas are called killers not because of their behavior toward humans, but because of the way they treat other ocean creatures. They are fierce, quick, and intelligent predators with huge appetites. Orcas will hunt fish, squid, penguins, seals, whales, and other dolphins. Nonetheless, there are no records of an orca killing a human.

DIRECTIONS For each of the following paragraphs, write a topic sentence that communicates the main idea.

1. Before 1966, the ice axes used in mountain climbing had straight blades. This limited the kinds of slopes that could be climbed. When Yvon Chouinard added a slight curve to the pick side of the ax, however, even the steepest slopes seemed attainable. It was, indeed, the beginning of a new sport called ice climbing.

2. The curved ice ax has allowed climbers to take on nearly vertical slopes that once seemed impossible. Now, armed with their axes, daring ice climbers prefer the extremely dangerous vertical slopes. Some of their favorite challenges are frozen waterfalls.

3. Frozen waterfalls are intensely beautiful. Climbing on such ice is like climbing on a diamond that sparkles blue one minute and yellow the next. In addition, ice climbers get a breathtaking view of the winter world below them. Ice climbers also enjoy the challenges of frozen waterfalls. All the challenges of climbing an entire mountain can be encountered by scaling a single frozen waterfall.

4. When ice climbers are on the side of a frozen waterfall, their arms and legs are in constant use. Each hand holds an ice ax. Strapped to each boot are crampons, which are a layer of two-inch spikes, some of which point forward to grip the ice. It takes strength to drive the ax into the ice. Even when a climber is not moving, each muscle is needed to hold on.

5. Many experienced mountain and rock climbers shy away from this dramatic and dangerous sport. Those who do attempt the sport of ice climbing tend to be well prepared. They must have the right boots, gloves, spikes, and other equipment. While climbing, they are very slow and careful.

-lack of self- study

-inability to manage timely

-negative attitude

Topic sentence : Some students fail to succeed in their studies due to three factors: a lack of self-study, an inability to manage time effectively, and a negative attitude.

     -Save time and money      

     -Sharpens the mind
     -Boosts brain power

          Topic sentence : Being structured while learning a language saves time and money, sharpens the intellect, and increases brain strength.

  - become more aggressive and anxious

  - imitate  their action

  - impact on their future lifestyle 

Topic sentence : Children watch too much violence on television will make them become more aggressive and anxious, imitate their action, impact on their future lifestyle 

 

Sports have a lot of good benefits for students. However, some people claim that competitive sports, both team and individual, should be eradicated from the school’s curriculum. Due to some reason, I strongly believe that such activities still play an important role in student's developments. In fact, sports help students keep fit and raise them good habits by doing exercise. Some competitive sports such as football, basketball or volleyball require players to move a lot which helps their body burn fat and calories and also release stress from school. In addition, competitive sports also help students to create connections between individuals and others. Playing in team is the easy way for students to make friends and improve their social skills. Lastly, competitive sports helps students to strive to do their best. It would be far more encouraging than any words because people often put more efforts if they have set goals for themselves. To conclude, I am convinced that it should not be removed from school curriculum with its undeniable benefits.