121.We must do it well, ________there are a lot of difficulties.

　　A.as if B.as though C.even though D.even as

　　122.________ difficult it may be,we are sure to stick to our principle.

　　A.How B.No matter how C.What D.No matter what

　　123.—It’s a long time__________I saw you last.

　　—Yes,and what a pity it is now that it will be a long time__________we see each other again.

　　A.before;since B.since;when C.since;before D.when;before

　　124.—Why didn’t you try your best to get on the bus?

　　—I tried to,but_________ I could,it started moving.

　　A.until B.when C.before D.after

　　125.The head of the company promised to deal with matters of this sort________ he returned to his office.

　　A.until B.while C.by the time D.the moment

　　126.—Did you remember to give Tom the key to his bedroom?

　　—Yes.I gave it to him________ I saw him.

　　A.while B.once C.suddenly D.the moment

　　127.He had already walked three or four miles_______ he saw a cart,half-full of hay,by the side of the road.

　　A.while B.when C.the moment D.unless

　　128.My grandpa sowed the flower seeds in the garden_____________ it was the best time for them to grow.

　　A.where B.when C.that D.until

　　129.I’d like to settle down somewhere__________________ the climate is mild and the sun shines all year long.

　　A.which B.that C.where D.when

　　130.Heat does not travel by connection in solid,because the solid does not move, _____.

　　A.so does a liquid B.so a liquid does C.as does a liquid D.so is a liquid