John passed his exam with a distinction. B: _______.

A. He was too lazy to succeed          B. He can't have studied very hard

C. He must have studied very hard  D. He needs studying harder

My car keys are possibly in the kitchen.

A. My car keys should be put in the kitchen

B. My car keys cannot be in the kitchen

C. I don’t know whether my car keys are in the kitchen.

D. My car keys might be in the kitchen

It was a mistake of you to lose your passport.

A. You shouldn't have lost your passport.      B. There must be a mistake in your passport.

C. You needn't have brought your passport.  D. Your passport must be lost.

It isn't obligatory to submit my assignment today

A. I mustn't submit my assignment today

B. My assignment must have been submitted today

C. I needn't submit my assignment today

D. My assignment is required to submit by today

In 1900 the world had no deaths from rabies. Scientists_____ wonderful vaccine.

A. has discovered              B. discovered

C. must have discovered D. should have discovered

She _________ , but luckily , a lifeguard spotted her and rescued her.

A. has drowned B. ought to drown C. could have drowned D. might drown

I would rather_____ poor but happy than become rich without happiness.

A. being B. be C. to be D. was

You're having a sore throat. You'd better_____ to the doctor.

A. to go B. went C. go D. going

He spent all that money last week. He_____ so much.

A. didn't need spend         B. didn't need spend

C. needn't have spent       D. didn't have to spend

He _____ all that money, so he could save some.

A. didn't need to spend      B. needn't have been spent

C. shouldn't spend             D. oughtn't to spend