问题 单项选择题

关于线程,下列叙述正确的是______。

A.线程本身也是一个程序,它自己能独立运行

B.多个线程中,每一个线程都有自己独立的一块内存空间、一组系统资源

C.线程就是一个程序内部的顺序控制流

D.多线程就是多次启动一个程序

答案

参考答案:C

解析: 线程本身并不是程序,而是一个程序内部的顺序控制流,它自己本身并不能运行,必须在程序中运行,所以选项A错误。对于进程而言,每个进程都有自己独立的一块内存空间、一组系统资源。而线程不同于进程,多个线程共享一块内存空间和一组系统资源,所有选项B错误。多线程指在一个程序中可以定义多个线程并同时运行它们,每个线程可以执行不同的任务,即在同一个程序中多行语句同时执行,而不是多次启动一个程序,所以选项D错误。多线程是针对一个程序而言的,代表着一个程序内部可以同时执行的线程个数。只有选项C叙述正确。

单项选择题
阅读理解

Wild Blue is a none-of-a-kind, geography-oriented exploration and adventure center for children aged 3 through 10.Our mission is to immerse(使沉浸于)children and their families in experiences that relate to the people,places and natural elements of the wonderful planet we live on.All our programs are developed and led by our own world-class team of explorers and educators.The following is a brief introduction to some of our classes:    

Global Kitchen

All over the world,people gather together to share meals.In this class, children will learn about the cuisine of a foreign country or region while they create a delicious snack. Recipes will be kid-friendly, and use ingredients(原料)from the country of origin.Your child will learn healthy,easy-to-create recipes he can bring home to share!

Documentary Filmmaking

This 50-minute video documentary film class is specially designed for our 6and 7 years old explorers.Classes will concentrate on the basics of visual storytelling and include subject discovery, story development, storyboard, filming,editing and presenting.Participants will work as a team to produce their own documentary, which will then be screened for friends and family at the course’s conclusion.

Exploring the Wonders of Earth

Designed specifically with our youngest explorers in mind, this semester-long program will expose your child to a wide variety of exciting scientific events that occur on our planet,from chocolate melting,to volcanoes erupting,to seeds sprouting.Through this course children will begin to develop an awareness of the science that makes the earth a marvelous place.

A World of Arts and Crafts

Whether you are seeking to simply extend your child’s time at Wild Blue or looking for a favorite pastime,we offer our own unique version of arts and crafts.Focusing on using found objects,this course encourages children to draw creative inspiration from cultures around the world.This course is available,upon request, as an additional class in your child’S schedule.

68.We can know from the passage that Wild Blue      

A.aims to urge people to protect the environment

B.is specially designed for children and teens

C.focuses on the relationship between people

D.permits adults to participate in its activities

69.Children who study documentary filmmaking     .

A.are supposed to work in teams

B.have to sign up with several friends

C.will learn everything about filmmaking

D.will make a documentary on their family

70.Those who take the“Exploring the Wonders of Earth” course can       .

A.learn to make chocolate

B.see volcanoes erupting in person

C.know more about exciting scientific events

D.make the world more marvelous

71.A World of Arts and Crafts is designed       .

A.for new beginners with artistic talent

B.for children to improve their drawing style

C.to help children learn about arts and cultures

D.to teach children how to spend their spare time