11 I waited ( ) his bus had left, and then I walked back to my apartment.
　　　① after　② by　③ until　④ while

12 ( ) I graduate from university, I will speak English fluently.
　　　① By the time　② Until　③ Even though　④ Upon

13 Look carefully ( ) you cross the street.
　　　① after　② before　③ though　④ unless

14 It was not long ( ) my aunt came.
　　　① soon　② during　③ by　④ before

15 ( ) I entered the room, I found my lost watch.
　　　① As soon as　② By the time　③ During　④ While

16 He wanted her to call him the ( ) she got home.
　　　① moment　② place　③ time　④ way

17 私の姿を見るやいなや彼は逃げ出した。
　　　( me / he / had / when / seen / hardly ) he ran away.

18 ( ) I know, no student has been able to solve this problem in ten minutes.
　　　① As long as　② Because　③ As far as　④ The moment

19 You may borrow my camera, ( ) you are careful with it.
　　　① while　② even if　③ when　④ as long as

20 I didn't have much time, ( ) I took a taxi.
　　　① because　② for　③ so　④ such

21 This car is ( ) expensive that I can't buy it.
　　　① so　② such　③ very　④ too

22 遅れないようにタクシーに乗りました。
　　　I took ( that / wouldn't / a / I / so / taxi ) be late.