Một vật nặng 2kg đang được treo cân bằng trên lò xo. Lực đàn hồi của lò xo khi đó bằng: A.1N B.10N C.2N D.20N

(3xy^2+6x^2y)÷3xy

x^2-5^2

Choose the correct word marked A, B, C or D to fill each blank in the following passage The British spend their free time in different ways. People generally use it to relax. But many people also take park (1)........... voluntary work, especially for charities. People spend a lot of their free time in the home, where (2)......... popular leisure activity is watching television, the average viewing time being 25 hours a week. People often (3).......... programs on video so that they can watch later. Reading is also a favourite way of spending leisure time. The British people (4)......... a lot of time reading newpapers and magazines. In the summer gardening is popular. And in winter it is often replaced by "Do-it-yourself", (5)............ people spend their time improving or repairing their homes. Many people have pets to look after: taking (6)........ dog for a daily walk is a regular routine. Câu 1: A.on B.in C.at D.for Câu 2: A.the most B.most C.more D.more than Câu 3: A.record B.scan C.print D.power Câu 4: A.spend B.spends C.spending D.to spend Câu 5: A.what B.why C.when D.while Câu 6: A.no article B.a C.an D.the

x^2+2xy+y^2+16