1.    The first ___astronaut____ to study the surface of Mars was Galileo Galilei. (astronomy)

2.    A Mars ___habitat____ is a place that humans can live in on Mars. (habitable)

3.    The space tourists will spend two days traveling to and from the ____orbiting___ space station. (orbit)

4.    The sensation of ____weightless___ , or zero gravity, happens when the effects of gravity are not felt. (weigh)

5.    The astronauts are performing NASA’s first routine __maintenance_____ outside the International Space Station. (maintain)

6.    On 5 October 1957 the Soviet Union ___succeed____ in putting the first man made satellite into orbit around the Earth. (success)

7.    The astronauts from many nations worked ___harmol]nically____ together to accomplish their work. (harmony)

8.    One of the basic ___requirements____ to join NASA is American citizenship. (require)

9.    John Young was one of NASA’s most ___experienced____ astronauts and the first astronaut to fly into space six times. (experience)

10.  The Apollo 11 moon landing was a ___historical____ achievement. (history)

a) \(\dfrac{4}{5}+\dfrac{3}{4}=\dfrac{31}{20}\)

b) \(\dfrac{5}{4}+\dfrac{5}{6}=\dfrac{25}{12}\)

c) \(\dfrac{9}{8}+\dfrac{5}{16}=\dfrac{23}{16}\)

d) \(\dfrac{39}{45}+\dfrac{13}{15}=\dfrac{26}{15}\)

\(\dfrac{1}{6}+\dfrac{5}{6}+\dfrac{1}{3}=\dfrac{8}{6}=\dfrac{4}{3}\)

\(\dfrac{5}{12}+\dfrac{1}{2}+\dfrac{2}{3}+\dfrac{3}{4}=\dfrac{7}{3}\)

it

v

v

it

them

v

her

them

v

it

any => some

longest => the longest

My dad is going to plant flowers in the garden

What are the plants you have for the weekend?

feelings

volcano eruption

scientists

disastrous

pollution

strength

encourages

popularity

savings

employment

loosen

proud

preservation

household

Áp dụng tính chất của đường phân giác ta có

\(\dfrac{AE}{EC}=\dfrac{AB}{BC};\dfrac{AF}{FB}=\dfrac{AC}{BC}\)

Mà \(AB=AC\left(gt\right)\)

\(\Rightarrow\dfrac{AE}{EC}=\dfrac{AF}{FB}\)

⇒ EF // BC

\(\Rightarrow\dfrac{EF}{DC}=\dfrac{AF}{AB}=\dfrac{AC}{AC+BC}\Leftrightarrow\dfrac{EF}{6}=\dfrac{5}{11}\Rightarrow EF=\dfrac{30}{11}\)

đồ học giỏi =))

vẫn mãi con số thứ 3 :>