What is the only means of preserving beauty, according to these lines from William Shakespeare's Sonnet 3?

Thou art thy mother's glass, and she in thee
Calls back the lovely April of her prime:
So thou through windows of thine age shall see
Despite of wrinkles this thy golden time.
But if thou live, remember'd not to be,
Die single, and thine image dies with thee.

the following key ideas correctly express the key sentence.

restate key idea: most people can learn to swim in ten short lessons.

restate key idea: the majority of water-accident victims require mouth-to-mouth breathing.

restate key idea: an empty, tightly closed gallon jug will support a tired swimmer.  

restate key idea: first aid is to prevent accidents as well as assist in rescue.

explanation: the key idea needs to have the same topic as the key sentence (drowning and safety).

the pronoun reference replaces a noun, but you have to make sure there's no room for confusion.

in the first sentence "her" could be referring to shely or to the sister. the answer there is "shelly called her sister and told her about the new baby."

in the second sentence "it" could be referring to the roof or the floor. the answer there is "since the roof leaks on the family room floor, we need to repair the roof."

the major theme of langston hughes’s montages of a dream deferred is the deferred, or delayed, american dream of african americans. the poem is about how african americans failed to achieve their goals in time:

this year, maybe, do you think i can graduate?

i’m already two years late.dropped out six months when i was seven,

a year when i was eleven,

then got put back when we come north.

to get through high high school at twenty's kind of late–

but maybe this year i can graduate.

the poem also depicts how african americans had to keep postponing their needs with a hope that someday they would be able to obtain what they desired:

maybe now i can have that white enamel stove

i dreamed about when we first fell in love

eighteen years ago.

but you know,

rooming and everything

then kids,

cold-water flat and all that.

but now my daughter’s married

and my boy's most grown–

quit school to work

and where we're moving

there ain't no stove–

maybe i can buy that white enamel stove!

however, despite their deferred dreams, the poem shows the refusal of african americans to give up easily and let go of their dreams of a better life. their dreams may have been delayed, but they did not lose hope.

is the answer