In the world,more than 30% of schools do not provide safe drinking water _____ about 570 million children.
本题考查固定搭配。provide sth. for sb. 意为“为某人提供某物”,此处所缺的介词是for。
You'd better _____ hard from now on,_____ you will fail in the exam.
本题考查had better do sth. 的用法和连词and、or的区别。句意:你最好从现在开始就努力学习,否则你考试会不及格。had better 后要跟动词原形,先排除 B 和 C;表示“否则”要用or,故答案为D。
—The light is on. When you leave,please _____.
—OK,I won't forget _____ it.
句意:——灯还开着呢。当你离开的时候,请把它关掉。——好的,我不会忘记做那件事的。表示“关灯”要用turn off,先排除C;forget to do sth. 意为“忘记做某事”,故答案为A。