The best alternative title for the passage will be______. A: A Study of Weed Communities B: The Importance of Studying How Plants Live in Communities C: How Herbicides May Affect Farm Land D: Weed Control by Means of Herbicides

16、【单选题】Why does Pecola identify herself with dandelions?A、It is a kind of weed.B、It is vulnerableC、It is usefulD、It is ignored and distained.

J. Bill and Royce planned to weed the field using an old burning tire.

Mud from the bottom of the pond can be used to ________ the crops. A: sow B: irrigate C: fertilize D: weed

Some will water the apple trees,______will weed the cotton fields. A: another B: the other C: the others D: other

Though many candidates are applying for the vacancy, we have to ______ the list to three. A: weed B: winnow C: surrogate D: draw

Whichtwowordsareclosestinmeaning?<br/><b>cycle</b><b>，</b><b>hawk</b><b>，</b><b>convey</b><b>，</b><b>extort</b><b>，</b><b>peddle</b><b>，</b><b>summon</b>

设A{a,b}，则P(A)×A = (   )。 A: A B: P（A） C: {<Φ,a>,<Φ,b>,<{a},a>,<{a},b>,<{b},a>,<{b},b>,<A,a>,<A,b>} D: {<a,,Φ,>,<b,,Φ,>,<a,{a}>,<b,{a}>,<a,{b}>,<b,{b}>,<a,A>,<b,A>}

以下哪段代码可以将A,B的值互换（） A: A=A^B; B=A^B;A=A^B B: A= A^B;A=A^B;B=A^B C: B= A^B; B=A^B; A=A^B D: B=A^B; A= A^B; A= A^B

若集合A={a，b}，B={ a，b，{ a，b }}，则（）。 A: A⊆B，且A∈B B: A∈B，且B⊆A C: A⊈B，且A∉B D: A∉B，且A⊈B