TASK DEFINITION: In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D". 
PROBLEM: [header] How to know if your dental fillings need replacing [title] Watch for tooth sensitivity. [step] If you have fillings that need replacement, you'll likely feel it first. Paying attention to the physical symptoms of old or decaying fillings can let you know if it's time to have your dentist replace them. <sep> (A) One sign that your fillings may need replacing is if you have tooth sensitivity to temperature, sweets, or pressure. [substeps] Pay attention when you bite into any cold, hot, or sweet foods. (B) Teeth sensitivity occurs when gums become severely stained with white blood. These white discolorations are mainly due to gum disease, but most commonly introduce a white blood cell colony to the side of your mouth. (C) Once your doctor notices an increase in tooth sensitivity, he or she can return you to the dentist. [substeps] Are your teeth hurt or moist? Severe tooth pain, cramping, sensitivity, or tingling are all signs that they need replacement. (D) [substeps] Bad tooth sensitivity is usually not a problem until it gets worse and you start to feel pain. You may experience sensitivity at night and bad teeth at the same time.

SOLUTION: A

PROBLEM: [header] How to be a safe teenage driver [title] Make sure to stick to the speed limit. [step] Even if you are running late somewhere, don't speed. It's better to get to your destination a few minutes later than planned than to be in an accident. <sep> (A) [substeps] If you can, use the designated speed limit as the number one way to stay safe. Say, " i'm going to slow down and stop at a crosswalk or change lanes. (B) [substeps] Always turn off your lights before you get to your destination. Check your vehicle for brake dust after each turn, as white brake dust can be far from safe. (C) Not only could speeding cause an accident, but it could result in you getting a speeding ticket! [title] Use common sense. [step] Wear your seat belt no matter what, and make sure not to get caught up in any distractions while driving, such as texting. (D) [title] If you know the shortest route to your destination, your first step is to stay calm and drive slowly. [step] There is no need to panic if you are in a secluded area so stop no more than you expect.

SOLUTION: C

PROBLEM: [header] How to buy natural beef [title] Know about regional certifications for food. [step] One of the first steps in buying natural beef is knowing what the labels on your food mean. These labels, and the meanings behind them, vary from country to country. <sep> (A) [substeps] Regional certifications are commonly performed by specialty food producers in countries similar to the united states. You will need the appropriate holiday agency, or regional psychologists for certain food brands you buy from, to buy one. (B) Check out some websites like international food-and-agriculture advisory. Keep in mind, however, that any animal listed on the label is legal to sell. (C) Knowing what they mean will help you decide on foods that you plan to grow in the future. [substeps] The united states association of food nutrition scientists (csa) has also compiled a list of pet foods that are natural based. (D) Understand how your country labels food in order to buy the best and most natural products on the commercial market. [substeps] In the end, food that is sold in commercial markets is only as good as the actual regulations enforced by the countries in which they are sold.

SOLUTION:
D