TJY3—1.5/11型风压继电器(1FYJ)的作用是作为电阻制动和空气制动的机械连锁。
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第一个广泛应用的超文本商品化软件是()。
A. Guide
B. KMS
C. HyperCard
D. NoteCard
旅游投诉是指旅游者为维护自身和他人的旅游合法权益,对损害其合法权益的旅游经营着和有关服务单位,以书面或口头形式向旅游行政管理部门提出投诉,请求处理的行为。
A. 正确
B. 错误
The CUSTOMERS table has these columns: CUSTOMER_ID NUMBER(4) NOT NULL CUSTOMER_NAME VARCHAR2(100) NOT NULL STREET_ADDRESS VARCHAR2(150) CITY_ADDRESS VARCHAR2(50) STATE_ADDRESS VARCHAR2(50) PROVINCE_ADDRESS VARCHAR2(50) COUNTRY_ADDRESS VARCHAR2(50) POSTAL_CODE VARCHAR2(12) CUSTOMER_PHONE VARCHAR2(20) The CUSTOMER_ID column is the primary key for the table. Which two statements find the number of customers? ()
A. SELECT TOTAL(*) FROM customer;
B. SELECT COUNT(*) FROM customer;
C. SELECT TOTAL(customer_id) FROM customer;
D. SELECT COUNT(customer_id) FROM customer;
E. SELECT COUNT(customers) FROM customer;
F. SELECT TOTAL(customer_name) FROM customer
吴大猷与其堂兄弟大业、大任、大立、都曾就读南开大学,被誉为“南开四吴”。
A. 正确
B. 错误