题目内容
注射成形塑料及橡胶时，模具温度比料筒温度高的是()。
查看答案
搜索结果不匹配？点我反馈
更多问题
Passage Three
Questions 23 to 26 are based on the passage you have just heard.
听力原文 Passage Three One of the greatest heartbreaks for firefighters occurs when they
fail to rescue a child from a burning building because the child—frightened by smoke and
noise—hides under a bed or in a closet and is later found dead. Saddest of all is when
children catch a glimpse of the masked firefighter but hide because they think they have
seen a monster. To prevent such tragedies, firefighter Eric Velez gives talks to children
in his community, explaining that they should never hide during a fire. He displays
firefighters’ equipment, including the oxygen mask, which he encourages his listeners to
play with and put on. “If you see us,” Velez tells them, “don’t hide. We are not
monsters. We have come to rescue you.” Velez gives his presentations in English and
Spanish. Growing up in San Francisco, he learned Spanish from his immigrant parents. Velez
—and other firefighters throughout North America who give similar presentations—will
never know how many lives they save through their talks, but it’s a fact that informative
speaking saves lives. For example, several months after listening to an informative speech,
Pete Gentry in North Carolina rescued his brother, who was choking on food, by using the
method taught by student speaker Julie Parris. In addition to saving lives, informative
speakers help people learn new skills, solve problems, and acquire fascinating facts about
the exciting world in which they live.
Questions 23 to 26 are based on the passage you have just heard.
23. Why do some children trapped in a burning building hide from masked firefighters？
只有在室温下处于玻璃态的高聚物才称为塑料。( )
由于塑化后的有机高分子材料粘性很大，充填模腔的能力很差，常需施加外力以使其强迫成形。( )
天然橡胶和合成橡胶都是在高弹态使用的高分子材料。( )
微信支付 
支付宝支付