Real interaction between teachers and students involves some effective activities, ________ students share information and solve problems by themselves．

A．when

B．which

C．that

D．where

Henry, who hurried home before dark so he could go for a run, ________ to wear his safety belt-a mistake 75％ of the US population make every day．

A．forgets

B．have forgot

C．had forgotten

D．will forget

Frank's success in public life ________ greatly to his ability to learn from observation and experience．

A．related

B．contributed

C．attached

D．owed

To know more news about CPPCC and NPC(两会), you can use the Internet or watch CCTV, or ________．

A．both

B．neither

C．some

D．more

This website has a high rate of clicks, which provides students with ________ plenty of information on ________ overseas study．

A．a; 不填

B．不填; 不填

C．a; the

D．the; the

On our way to school, suddenly it began to rain, and we hurried to take ________ under a big tree．

A．recovery

B．notice

C．advantage

D．shelter

I can still remember that it is since the 1990's, ________ we began to use cell phones, ________ the number of mobile users has greatly increased．

A．while; when

B．when; what

C．before; that

D．when; that

Every one of us must know this：________ we live can we save the earth．

A．by changing the way only

B．by only changing the way

C．only by changing the way

D．by changing only the way

During the period of recent terrorist activities, people ________ not to touch an unattended bag．

A．had always been warned

B．were always being warned

C．are always warning

D．always warned