问题
单项选择题
调节阀阀体内有上下两阀座与阀芯,适用于压差较大的场合,缺点是泄漏量较大的是()调节阀。
A.直通单座
B.直通双座
C.角形
D.三通
答案
参考答案:B
调节阀阀体内有上下两阀座与阀芯,适用于压差较大的场合,缺点是泄漏量较大的是()调节阀。
A.直通单座
B.直通双座
C.角形
D.三通
参考答案:B
Lifelong Learning (终身学习) In the past, when students graduated from college and got jobs, only some of them went on with their study. But today, lifelong learning is becoming more and more common. Lucy, who is forty, teaches physics at a college in Boston. “Next term, I’ll teach some of my classes by using the Internet. This is the way of teaching that I’ve never used before,” says Lucy, “These days, I am taking a class to learn how to teach in this way. If not, I will lose my jobs.” At the same time, Lucy’s seventy-year-old parents, who live in New York, are taking an art history class online. “We love this subject,” says her father, “and we learn it to enjoy ourselves. You see we can study with people all over the world. What fun it is to learn like this!”
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